Tutor:

New! Get regular updates about newly solved problems via algebra.com's RSS system.

---

Recent problems solved by 'solver91311'

solver91311 answered: 16882 problems
Jump to solutions: 0..29 , 30..59 , 60..89 , 90..119 , 120..149 , 150..179 , 180..209 , 210..239 , 240..269 , 270..299 , 300..329 , 330..359 , 360..389 , 390..419 , 420..449 , 450..479 , 480..509 , 510..539 , 540..569 , 570..599 , 600..629 , 630..659 , 660..689 , 690..719 , 720..749 , 750..779 , 780..809 , 810..839 , 840..869 , 870..899 , 900..929 , 930..959 , 960..989 , 990..1019 , 1020..1049 , 1050..1079 , 1080..1109 , 1110..1139 , 1140..1169 , 1170..1199 , 1200..1229 , 1230..1259 , 1260..1289 , 1290..1319 , 1320..1349 , 1350..1379 , 1380..1409 , 1410..1439 , 1440..1469 , 1470..1499 , 1500..1529 , 1530..1559 , 1560..1589 , 1590..1619 , 1620..1649 , 1650..1679 , 1680..1709 , 1710..1739 , 1740..1769 , 1770..1799 , 1800..1829 , 1830..1859 , 1860..1889 , 1890..1919 , 1920..1949 , 1950..1979 , 1980..2009 , 2010..2039 , 2040..2069 , 2070..2099 , 2100..2129 , 2130..2159 , 2160..2189 , 2190..2219 , 2220..2249 , 2250..2279 , 2280..2309 , 2310..2339 , 2340..2369 , 2370..2399 , 2400..2429 , 2430..2459 , 2460..2489 , 2490..2519 , 2520..2549 , 2550..2579 , 2580..2609 , 2610..2639 , 2640..2669 , 2670..2699 , 2700..2729 , 2730..2759 , 2760..2789 , 2790..2819 , 2820..2849 , 2850..2879 , 2880..2909 , 2910..2939 , 2940..2969 , 2970..2999 , 3000..3029 , 3030..3059 , 3060..3089 , 3090..3119 , 3120..3149 , 3150..3179 , 3180..3209 , 3210..3239 , 3240..3269 , 3270..3299 , 3300..3329 , 3330..3359 , 3360..3389 , 3390..3419 , 3420..3449 , 3450..3479 , 3480..3509 , 3510..3539 , 3540..3569 , 3570..3599 , 3600..3629 , 3630..3659 , 3660..3689 , 3690..3719 , 3720..3749 , 3750..3779 , 3780..3809 , 3810..3839 , 3840..3869 , 3870..3899 , 3900..3929 , 3930..3959 , 3960..3989 , 3990..4019 , 4020..4049 , 4050..4079 , 4080..4109 , 4110..4139 , 4140..4169 , 4170..4199 , 4200..4229 , 4230..4259 , 4260..4289 , 4290..4319 , 4320..4349 , 4350..4379 , 4380..4409 , 4410..4439 , 4440..4469 , 4470..4499 , 4500..4529 , 4530..4559 , 4560..4589 , 4590..4619 , 4620..4649 , 4650..4679 , 4680..4709 , 4710..4739 , 4740..4769 , 4770..4799 , 4800..4829 , 4830..4859 , 4860..4889 , 4890..4919 , 4920..4949 , 4950..4979 , 4980..5009 , 5010..5039 , 5040..5069 , 5070..5099 , 5100..5129 , 5130..5159 , 5160..5189 , 5190..5219 , 5220..5249 , 5250..5279 , 5280..5309 , 5310..5339 , 5340..5369 , 5370..5399 , 5400..5429 , 5430..5459 , 5460..5489 , 5490..5519 , 5520..5549 , 5550..5579 , 5580..5609 , 5610..5639 , 5640..5669 , 5670..5699 , 5700..5729 , 5730..5759 , 5760..5789 , 5790..5819 , 5820..5849 , 5850..5879 , 5880..5909 , 5910..5939 , 5940..5969 , 5970..5999 , 6000..6029 , 6030..6059 , 6060..6089 , 6090..6119 , 6120..6149 , 6150..6179 , 6180..6209 , 6210..6239 , 6240..6269 , 6270..6299 , 6300..6329 , 6330..6359 , 6360..6389 , 6390..6419 , 6420..6449 , 6450..6479 , 6480..6509 , 6510..6539 , 6540..6569 , 6570..6599 , 6600..6629 , 6630..6659 , 6660..6689 , 6690..6719 , 6720..6749 , 6750..6779 , 6780..6809 , 6810..6839 , 6840..6869 , 6870..6899 , 6900..6929 , 6930..6959 , 6960..6989 , 6990..7019 , 7020..7049 , 7050..7079 , 7080..7109 , 7110..7139 , 7140..7169 , 7170..7199 , 7200..7229 , 7230..7259 , 7260..7289 , 7290..7319 , 7320..7349 , 7350..7379 , 7380..7409 , 7410..7439 , 7440..7469 , 7470..7499 , 7500..7529 , 7530..7559 , 7560..7589 , 7590..7619 , 7620..7649 , 7650..7679 , 7680..7709 , 7710..7739 , 7740..7769 , 7770..7799 , 7800..7829 , 7830..7859 , 7860..7889 , 7890..7919 , 7920..7949 , 7950..7979 , 7980..8009 , 8010..8039 , 8040..8069 , 8070..8099 , 8100..8129 , 8130..8159 , 8160..8189 , 8190..8219 , 8220..8249 , 8250..8279 , 8280..8309 , 8310..8339 , 8340..8369 , 8370..8399 , 8400..8429 , 8430..8459 , 8460..8489 , 8490..8519 , 8520..8549 , 8550..8579 , 8580..8609 , 8610..8639 , 8640..8669 , 8670..8699 , 8700..8729 , 8730..8759 , 8760..8789 , 8790..8819 , 8820..8849 , 8850..8879 , 8880..8909 , 8910..8939 , 8940..8969 , 8970..8999 , 9000..9029 , 9030..9059 , 9060..9089 , 9090..9119 , 9120..9149 , 9150..9179 , 9180..9209 , 9210..9239 , 9240..9269 , 9270..9299 , 9300..9329 , 9330..9359 , 9360..9389 , 9390..9419 , 9420..9449 , 9450..9479 , 9480..9509 , 9510..9539 , 9540..9569 , 9570..9599 , 9600..9629 , 9630..9659 , 9660..9689 , 9690..9719 , 9720..9749 , 9750..9779 , 9780..9809 , 9810..9839 , 9840..9869 , 9870..9899 , 9900..9929 , 9930..9959 , 9960..9989 , 9990..10019 , 10020..10049 , 10050..10079 , 10080..10109 , 10110..10139 , 10140..10169 , 10170..10199 , 10200..10229 , 10230..10259 , 10260..10289 , 10290..10319 , 10320..10349 , 10350..10379 , 10380..10409 , 10410..10439 , 10440..10469 , 10470..10499 , 10500..10529 , 10530..10559 , 10560..10589 , 10590..10619 , 10620..10649 , 10650..10679 , 10680..10709 , 10710..10739 , 10740..10769 , 10770..10799 , 10800..10829 , 10830..10859 , 10860..10889 , 10890..10919 , 10920..10949 , 10950..10979 , 10980..11009 , 11010..11039 , 11040..11069 , 11070..11099 , 11100..11129 , 11130..11159 , 11160..11189 , 11190..11219 , 11220..11249 , 11250..11279 , 11280..11309 , 11310..11339 , 11340..11369 , 11370..11399 , 11400..11429 , 11430..11459 , 11460..11489 , 11490..11519 , 11520..11549 , 11550..11579 , 11580..11609 , 11610..11639 , 11640..11669 , 11670..11699 , 11700..11729 , 11730..11759 , 11760..11789 , 11790..11819 , 11820..11849 , 11850..11879 , 11880..11909 , 11910..11939 , 11940..11969 , 11970..11999 , 12000..12029 , 12030..12059 , 12060..12089 , 12090..12119 , 12120..12149 , 12150..12179 , 12180..12209 , 12210..12239 , 12240..12269 , 12270..12299 , 12300..12329 , 12330..12359 , 12360..12389 , 12390..12419 , 12420..12449 , 12450..12479 , 12480..12509 , 12510..12539 , 12540..12569 , 12570..12599 , 12600..12629 , 12630..12659 , 12660..12689 , 12690..12719 , 12720..12749 , 12750..12779 , 12780..12809 , 12810..12839 , 12840..12869 , 12870..12899 , 12900..12929 , 12930..12959 , 12960..12989 , 12990..13019 , 13020..13049 , 13050..13079 , 13080..13109 , 13110..13139 , 13140..13169 , 13170..13199 , 13200..13229 , 13230..13259 , 13260..13289 , 13290..13319 , 13320..13349 , 13350..13379 , 13380..13409 , 13410..13439 , 13440..13469 , 13470..13499 , 13500..13529 , 13530..13559 , 13560..13589 , 13590..13619 , 13620..13649 , 13650..13679 , 13680..13709 , 13710..13739 , 13740..13769 , 13770..13799 , 13800..13829 , 13830..13859 , 13860..13889 , 13890..13919 , 13920..13949 , 13950..13979 , 13980..14009 , 14010..14039 , 14040..14069 , 14070..14099 , 14100..14129 , 14130..14159 , 14160..14189 , 14190..14219 , 14220..14249 , 14250..14279 , 14280..14309 , 14310..14339 , 14340..14369 , 14370..14399 , 14400..14429 , 14430..14459 , 14460..14489 , 14490..14519 , 14520..14549 , 14550..14579 , 14580..14609 , 14610..14639 , 14640..14669 , 14670..14699 , 14700..14729 , 14730..14759 , 14760..14789 , 14790..14819 , 14820..14849 , 14850..14879 , 14880..14909 , 14910..14939 , 14940..14969 , 14970..14999 , 15000..15029 , 15030..15059 , 15060..15089 , 15090..15119 , 15120..15149 , 15150..15179 , 15180..15209 , 15210..15239 , 15240..15269 , 15270..15299 , 15300..15329 , 15330..15359 , 15360..15389 , 15390..15419 , 15420..15449 , 15450..15479 , 15480..15509 , 15510..15539 , 15540..15569 , 15570..15599 , 15600..15629 , 15630..15659 , 15660..15689 , 15690..15719 , 15720..15749 , 15750..15779 , 15780..15809 , 15810..15839 , 15840..15869 , 15870..15899 , 15900..15929 , 15930..15959 , 15960..15989 , 15990..16019 , 16020..16049 , 16050..16079 , 16080..16109 , 16110..16139 , 16140..16169 , 16170..16199 , 16200..16229 , 16230..16259 , 16260..16289 , 16290..16319 , 16320..16349 , 16350..16379 , 16380..16409 , 16410..16439 , 16440..16469 , 16470..16499 , 16500..16529 , 16530..16559 , 16560..16589 , 16590..16619 , 16620..16649 , 16650..16679 , 16680..16709 , 16710..16739 , 16740..16769 , 16770..16799 , 16800..16829 , 16830..16859 , 16860..16889, >>Next

Rational-functions/240218: determine which functions are polynomial functions and if they are state the degree f(x)=3x^5/2x+1 g(X)=3x^2+5^1/2-1 h(x)=3 f(x)=2x^3+3.14x+1/2 1 solutions Answer 176072 by solver91311(16897)   on 2009-11-18 01:25:49 (Show Source): You can put this solution on YOUR website! f(x) is not a polynomial function. f(x) is a rational function composed of the quotient of two polynomial functions. g(x) is a polynomial function because although it has a non-integer exponent, that exponent is not on a variable (unless you mis-typed it and it is supposed to be 5x^1/2) g(x) is degree 2. h(x) is a polynomial function of degree 0. Remember so you can re-write The other f(x) is a polynomial function of degree 3. Nothing says the coefficients have to be integers (or rational or even real, for that matter) John

Polynomials-and-rational-expressions/240170: it says max went shopping and spent 3/7 of his money on a new pair of shoes.Then he spends 2/5 of his money on a new shirt. what fraction of his money did max spend? 1 solutions Answer 176071 by solver91311(16897)   on 2009-11-18 01:10:55 (Show Source): You can put this solution on YOUR website! There is a problem with the way you stated your question. Did he spend 2/5 of the money he started with on the new shirt, or 2/5 of the money he had left after he bought the shoes? If it is the first way: If it is the second way: John

Quadratic_Equations/240199: Evaluate each given value of the function f(x) if f(x) =6-2x Find f(0) Find f(-2) 1 solutions Answer 176070 by solver91311(16897)   on 2009-11-18 00:53:33 (Show Source): You can put this solution on YOUR website! If Then John

Permutations/240223: How many five-letter passwords can be made if no letters are repeated? 1 solutions Answer 176069 by solver91311(16897)   on 2009-11-18 00:28:25 (Show Source): You can put this solution on YOUR website! 26 ways to pick the first letter. For each of those ways, there are 25 ways to pick the second letter (one less because letters cannot be repeated). So 26 times 25 ways to pick the first two letters. Then 24 ways for the third letter and so on. 26 X 25 X 24 X 23 X 22. You do the arithmetic. John

Complex_Numbers/240201: hi again =] i have a similiar question to the previous one, using the property of exponents can you write the complex number in standard form? 2+i^2 and 5-i^4 thank you! 1 solutions Answer 176062 by solver91311(16897)   on 2009-11-17 23:34:10 (Show Source): You can put this solution on YOUR website! Anything to the zero power is 1 by definition. Anything to the 1 power is itself. Definition of i The mod function returns the remainder from integer division. is the remainder when is divided by . John

Linear-equations/240128: How do I graph y > -2x + 3? 1 solutions Answer 176037 by solver91311(16897)   on 2009-11-17 20:30:35 (Show Source): You can put this solution on YOUR website! Step 1: Graph the equation except that since the original inequality has a symbol rather than a symbol, construct the graph using a dashed line. Step 2: Pick a test point that is NOT on the line. Since this line does not pass through the origin, the point (0,0) is an excellent choice. Step 3: Substitute the coordinates from the point you selected in the previous step for the variables in your original inequality. Perform any necessary arithmetic. Step 4: If the result of step 3 is a true statement, shade in the half-plane that contains the test point. If the result is a false statement, shade in the half-plane that does NOT contain the test point. Your solution set is the shaded area. Since the line is dashed, points on the line are NOT included in the solution set. John

Geometry_proofs/240126: Given: L is the midpoint of line segment IE, line segment NE is congruent to NI. Prove that line segment NI bisects angle INE 1 solutions Answer 176028 by solver91311(16897)   on 2009-11-17 20:07:44 (Show Source): You can put this solution on YOUR website! You can't prove that NI bisects angle INE. That's because NI doesn't bisect INE. Now, if you were just being careless and actually meant to say "prove that NL bisects angle INE", then proceed thus: (Note: This system won't render the congruence symbol, so I have substituted the identity symbol (≡) ≡ Given. ≡ Definition of midpoint ≡ Reflexive Property of Equality ≡ SSS ≡ CPCTC bisects Definition of Angle Bisector John

Miscellaneous_Word_Problems/240105: A wire is used to anchor a 20 foot high pole. One end of the wire is attached to the top of the pole. The other end is fastened to a stake five feet away from the bottom of the pole. Find the length of the wirse, to the nearest tenth of a foot. Can someone help me? - not sure how to start the problem....thank you. 1 solutions Answer 176027 by solver91311(16897)   on 2009-11-17 20:05:33 (Show Source): You can put this solution on YOUR website! The first thing that you have to do is presume that the pole is exactly perpendicular to the ground in the direction of the point where the wire is attached to the ground. That way you have a right triangle and that is the only way you can solve this problem with the information given. Now that you know you have a right triangle, one leg of the triangle is 20 feet because that is the length of the pole from the surface of the ground to the top , and the other leg is 5 feet because that is the distance from the base of the pole to the point where the wire is attached to the ground. Now just apply Pythagoras to calculate the measure of the hypotenuse of the triangle. Let be the length of the wire. Time to get out your calculator. Remember to round off according to the problem instructions. By the way, the round-off instructions in the problem are inappropriate. The results of a computation involving measurements should never be reported to a greater precision than the least precise of the given measurements. That means that, given the fact that the measurements here given to the nearest foot, you should actually report your answer to the nearest whole foot. On the other hand, had the given measurements been reported as 20.0 feet and 5.0 feet, then reporting the answer to the nearest tenth of a foot would be correct. All of that notwithstanding, follow the problem instructions. John

Human-and-algebraic-language/240097: How do you set up this word problem (& others like it)? A mother is eighteen years older than her son. She was three times as old as he was one year ago. How old are they now? 1 solutions Answer 176022 by solver91311(16897)   on 2009-11-17 19:47:54 (Show Source): You can put this solution on YOUR website! Let represent the mother's age. Let represent the son's age. Then the first thing we know is: One year ago, mother was , and the son was , and the second thing we know is: Now you have two 2-variable linear equations. Solve the system. The ordered pair will give you your answers. John

Travel_Word_Problems/240099: Two cars depart form the same place. One heads north at a certain speed, and the other car heads east at a speed 7mph faster than the first car. After one hour the cars are 17 miles apart. How fast is each car traveling? 1 solutions Answer 176019 by solver91311(16897)   on 2009-11-17 19:42:42 (Show Source): You can put this solution on YOUR website! I already answered this problem today, but here it is again in case you missed it. If you are going miles per hour for 1 hour, you must have traveled miles. Since east is 90 degrees from north, apply Pythagoras: Just solve for John

Divisibility_and_Prime_Numbers/240094: What is the smallest positive number divisible by four primes? 1 solutions Answer 176018 by solver91311(16897)   on 2009-11-17 19:39:39 (Show Source): You can put this solution on YOUR website! I presume you mean "what is the smallest positive number divisible by four different primes?" If that is the case, you are looking for the product of the four smallest primes. The smallest prime is 2. 1 is not prime, by definition. On the other hand, if your "four primes" can all be the same prime, then the answer is John

Linear-systems/240096: a system of linear equations that has the point (4,-7) as it's solution??? 1 solutions Answer 176017 by solver91311(16897)   on 2009-11-17 19:35:55 (Show Source): You can put this solution on YOUR website! Sorry, but there is no verb in your question. I can't understand what it is that you want to do. John

Triangles/240083: can a right triangle have more than 1 right angle? 1 solutions Answer 176016 by solver91311(16897)   on 2009-11-17 19:34:27 (Show Source): You can put this solution on YOUR website! The following answer applies to a right triangle in a Euclidian plane. The sum of the measures of the interior angles of ANY triangle is 180° A right angle measures 90° If a triangle had two right angles, then the sum of the measures of those two angles would be 90° + 90° = 180°. That would leave 0° for the third angle. So, in a word, the answer to your question is: No. A triangle on the surface of a sphere, torus, or any sort of Reimann Surface has different properties. John

Linear-systems/240071: Solve by graphing. x=-y (can't figure out slope) x+y=4 Can't figure out where the two points meet. 1 solutions Answer 176015 by solver91311(16897)   on 2009-11-17 19:19:51 (Show Source): You can put this solution on YOUR website! You really don't need to figure the slope, you just need to perform the following steps once for each of your equations. Step 1: Select a value for . It can be anything you want, but I suggest selecting a small integer. Step 2: Substitute the selected value for in the equation, and then do the arithmetic to solve the equation for Step 3: Create an ordered pair using the value of you selected in Step 1 and the value of you calculated in Step 2. Step 4: Plot the ordered pair from Step 3 on your coordinate plane. Step 5: Repeat Steps 1 through 4 once more using a different value for . Step 6: Draw a line through the two plotted points. Once you have graphed both lines, see where they intersect. That is, if they intersect. If you end up with two separate lines that do not intersect, then your solution set is the empty set. If you end up with two lines that do intersect in one point, your solution set is the ordered pair representing that point of intersection. If you end up with one line right on top of the other, then your solution set is the set of ordered pairs that satisfies either of the two equations. Such a set has in infinite number of elements. On the other hand, if you do feel the need to determine the slope, then solve each of the equations for . That means do whatever is necessary (and follows the rules of algebra) to get all by itself on the left-hand side of the equal sign and everything else on the right-hand side. For your first one: Rewrite it: Multiply by -1: Once a two variable linear equation is solved for , then the equation is in slope-intercept form. That means that the slope is the coefficient on the term. The coefficient on your term is -1. Hence the slope is -1. Do your other one the same way. By the way: Congratulations. This is my 5000th answer on this site. You don't win anything and neither do I, but I just wanted to share. John

Quadratic_Equations/239988: Doing a quadratic equation problem, i cam across a problem. the equation i got was x^2-6c-3=0. When plugging this problem into the equation, x=-b+/-(sqrt(b^2+4ac))/2a, I did not know if you could plug the b value (-3) into the place of -b or if you had to make it a positive b. 1 solutions Answer 176013 by solver91311(16897)   on 2009-11-17 19:04:45 (Show Source): You can put this solution on YOUR website! If is truly your equation, then if you compare it to the general form of a quadratic: that , , and . However, if that is the case, then there is no need for the quadratic formula because: Although, if you insist on using the quadratic formula, you will find that: reduces to the same answer. If you actually meant , that is another story, and then I'm curious where you got the idea that . John

Polygons/239990: how many side does a regular polygon have if the sum of its interior angles measures 2700 1 solutions Answer 175966 by solver91311(16897)   on 2009-11-17 16:36:44 (Show Source): You can put this solution on YOUR website! The sum of the interior angles of a convex -gon is given by: degrees. So, since you know the sum of the angles (2700) you can say: Now all you need to do is solve for to get the number of angles which is the same as the number of sides. This works whether the polygon is regular or not. John

Linear-equations/239978: So I need help with a word problem. I am pretty sure that i have to write it in y=mx+b form but I'm having a lot of trouble. I've only gotten as far as solving for slope but thats about it. Here it is. After being in business for a year, you discover that you are selling more boxes then you expected. you find that this is due to a larger base of customers. You find for the last several months you have consistently sold 325 boxes of markers at $23.50 per box. You continue to assume that if you charge $30 per box that you will sell 0 boxes. Use (23.5, 325) and (30,0) to find the new linear demand function. 1 solutions Answer 175963 by solver91311(16897)   on 2009-11-17 16:31:02 (Show Source): You can put this solution on YOUR website! Since you have two ordered pairs, you need to use the two point form of the equation of a line: Where and are your two given points, namely and Make the indicated substitutions and then do the arithmetic. In order to express this as a function, you need to put your result into slope-intercept form, namely by solving for John

Numbers_Word_Problems/239961: the sum of three consective odd intergers is 357 1 solutions Answer 175954 by solver91311(16897)   on 2009-11-17 16:01:00 (Show Source): You can put this solution on YOUR website! I don't know what intergers are. If you mean "the sum of three consecutive odd integers is 357," I would say that is a fascinating fact. Now is there some reason that you could not take the time to actually ask a question? There are a whole myriad of things that you could actually want based on the statement that I think you intended to make, namely: 1. What are the integers? 2. What is the smallest integer? 3. What is the largest integer? 4. What is the product of the three integers? (alternatively, the product of the smallest and largest, or smallest and middle, etc.) 5. How do you set up the problem so that the answers to any of the above can be determined? Not having any specific instructions about what you want, I guess I'll answer number 5: Let represent the smallest of the three consecutive odd integers. The next consecutive integer is one more than that, but the next consecutive integer to an odd integer is an even integer. To get to the next consecutive odd integer, you must add 2. Hence, represents the next consecutive odd integer. The one after that has to be The sum of these three integers is 357. "Sum" means add and "is" means equals, so: Just solve for to discover the first integer. Add 2 to get the second, and add 2 more to find the third. John

Angles/239963: This problem has a picture with it so I will explain it the best that I can. CD is the midsegment that measure is 6. The other meausure given is AB which is 4x-18. The problem says to find x. Please help. 1 solutions Answer 175951 by solver91311(16897)   on 2009-11-17 15:43:21 (Show Source): You can put this solution on YOUR website! Not anywhere near enough information. You have to describe your diagram in detail using the correct terminology. Otherwise we are just guessing at what you have. John

Permutations/239964: ann has 7 books she wants to put on her bookshelf how many posible arrangments are there? 1 solutions Answer 175950 by solver91311(16897)   on 2009-11-17 15:40:52 (Show Source): You can put this solution on YOUR website! Presuming that they are 7 different books, there are 7 ways to pick the first book. Then for each of those ways, there are 6 ways to pick the second book. Hence there are 42 ways to arrange the first two books. Then for each of those 42 ways there are 5 ways to select the third book, so 42 times 5...continue this process until you have selected all the books. Mathematical shorthand: John

decimal-numbers/239962: how do i change a percent to a decimal? 1 solutions Answer 175949 by solver91311(16897)   on 2009-11-17 15:37:25 (Show Source): You can put this solution on YOUR website! Move the decimal point two places to the left. John

Angles/239965: What is the sum of the measures of the interior angles of a convex decagon? Please help? 1 solutions Answer 175948 by solver91311(16897)   on 2009-11-17 15:36:44 (Show Source): You can put this solution on YOUR website! The sum of the interior angles of a convex -gon is given by: degrees. Hint: A decagon has 10 sides and therefore 10 angles. John

Trigonometry-basics/239955: Solve sin 2x = 3 cos x for all values of x. Thanks a lot for your help! 1 solutions Answer 175947 by solver91311(16897)   on 2009-11-17 15:33:27 (Show Source): You can put this solution on YOUR website! But So: Multiply by However the range of the function is Therefore the solution set of the equation: is the empty set, John

Exponents-negative-and-fractional/239956: I need to use the variables a= -1 b= -2, c= -3, d= -4 and the answer needs to equal 27. Can you help me come up with solutions for this problem? 1 solutions Answer 175946 by solver91311(16897)   on 2009-11-17 15:19:38 (Show Source): You can put this solution on YOUR website! It depends. Can you use the variables more than once each? Are there any restrictions on the arithmetic operations that you can use? Must you use each value at least once? Can you use numeric constants as well as the variables? You have to tell us the whole problem or we have to guess. If we guess wrong, which is very likely in this case, we tell you wrong. Then you have to unlearn the wrong thing before you can learn the right thing. John

Numbers_Word_Problems/239922: Two cars depart from the same place. One heads north at a certain speed, and the other car heads east at a speed 7mph faster than the first car. After one hour the cars are 17 miles apart. How fast is each traveling? 1 solutions Answer 175929 by solver91311(16897)   on 2009-11-17 13:59:37 (Show Source): You can put this solution on YOUR website! If you are going miles per hour for 1 hour, you must have traveled miles. Since east is 90 degrees from north, apply Pythagoras: Just solve for John

Rational-functions/239915: Simplify: 2 / 2-4i 1 solutions Answer 175927 by solver91311(16897)   on 2009-11-17 13:54:07 (Show Source): You can put this solution on YOUR website! That depends on whether you mean Which simply becomes Or Which requires that you rationalize the denominator by multiplying by 1 in the form of the conjugate of your complex denominator divided by itself. The conjugate of a complex number is . So you need to multiply your expression by Since the denominator is now the factors of the difference of two squares, the imaginary part will disappear. I'll let you do your own arithmetic, but remember John

Travel_Word_Problems/239900: Let?s say that you are driving on a straight route to a set destination, and you can drive at any speed you like. You stop for a few minutes but when you arrive at the halfway point, you discover that you have averaged only 20 miles per hour. So you decide to forego any more stops and drive fast enough to average 40 miles per hour for the entire trip. If you keep a steady speed, how fast should you drive? 1 solutions Answer 175922 by solver91311(16897)   on 2009-11-17 13:23:15 (Show Source): You can put this solution on YOUR website! You can't do it even if you went the speed of light. Let's look at a specific example first. Let's say the whole trip was 40 miles. Then to average 40 mph over the entire trip, you would have to make the entire trip in 1 hour. But since you only managed 20 mph for the first 20 miles of the trip (halfway), it took the entire hour to get to the halfway point. No matter how fast you go, you can't complete the last half of the trip in zero time. In general, Let represent the time to travel halfway, and let represent the time for the entire trip. If is the distance traveled at 20 mph, then is the entire distance. The first half of the trip can be described as: And the entire trip can be described as: But Which means that Impossible because if we let be the time for the second half, we know from the fact that must be true so if , then , and that simply cannot be. John

Equations/239901: factor x^2+7x+12 1 solutions Answer 175917 by solver91311(16897)   on 2009-11-17 13:02:20 (Show Source): You can put this solution on YOUR website! Hint: 3 + 4 = 7 3 X 4 = 12 John

Proportions/239889: how would you solve a cross multipliction for a proportion here is the promble : 4 apples 12 apples --------- = ----------- $1.60 X 1 solutions Answer 175916 by solver91311(16897)   on 2009-11-17 13:00:59 (Show Source): You can put this solution on YOUR website! What's a "promble"? Cross-multiply: The numerator on the left times the denominator on the right (for your situation that would be 4 times X) is equal to the denominator on the right times the numerator on the left (1.60 X 12). You end up with: Just solve for John

Travel_Word_Problems/239884: I can not find the correct formula for the following problem: Tina runs 10 miles in 70 minutes. How long does it take her to run 7 miles? I have tried the Distance= rate x time but it doesn't make sense. 1 solutions Answer 175915 by solver91311(16897)   on 2009-11-17 12:33:34 (Show Source): You can put this solution on YOUR website! If you know the rate and the time and want to calculate the distance, use Distance = Rate X Time: If you know the distance and the rate and want to calculate the time, take and divide both sides by to get If you know the distance and the time and want to calculate the rate, take and divide both sides by to get So you need to first use where to get the rate, and then use where to get the time. Always remember to pay attention to the units of measure. If you just divide 10 miles by 70 minutes, you are going to get miles per minute -- NOT miles per hour. John

Numeric_Fractions/239885: If the sum of a number and two is doubled, the result is six less than three times the number. Find the number. 1 solutions Answer 175913 by solver91311(16897)   on 2009-11-17 12:22:10 (Show Source): You can put this solution on YOUR website! Let represent the number Then the sum of the number and two is: Double that: Which can be written: Three times the number is: Six less than that: "Is" means equals, so: Just solve for John