# See tutors' answers!

Algebra ->  Tutoring on algebra.com -> See tutors' answers!      Log On

 Tutoring Home For Students Tools for Tutors Our Tutors Register Recently Solved
 By Tutor
| By Problem Number |

Tutor:

# Recent problems solved by 'Earlsdon'

Earlsdon answered: 6285 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, >>Next

 Expressions-with-variables/152578: Please help me solve this problem: What is 7 times the sum of M and 6?1 solutions Answer 112154 by Earlsdon(6291)   on 2008-08-19 21:13:51 (Show Source): You can put this solution on YOUR website!7 times the sum of M and 6 is expressed by: 7(M+6) and if you expand this, it becomes: 7M+42
 Surface-area/152571: How many 1/2 inch square tiles to cover a ball 9 inches in diameter? Thanks I can't find my formula book and I am 79 years old. (retired aerospace engineer)1 solutions Answer 112153 by Earlsdon(6291)   on 2008-08-19 21:10:37 (Show Source): You can put this solution on YOUR website!The surface area of a sphere with diameter D is given by:
 Expressions-with-variables/152595: the number of gallons in q quarts1 solutions Answer 112151 by Earlsdon(6291)   on 2008-08-19 20:53:24 (Show Source): You can put this solution on YOUR website!Since there are 4 qts in 1 gallon, you would divide the number of quarts (q) by 4 to find the number of gallons, so...
 Linear_Equations_And_Systems_Word_Problems/152592: Yesterday there were 5 times as many girls as boys in Miss Miriam's preschool. Today 4 more boys joined the preschool. Now there are 3 times as many girls as boys. How many children are now attending the preschool? So far I know that if you let "b" equal boys and "g" equal girls the first equation is 5b=g. I also know that I am looking for "x" the total amount of children in the school or b+g=x. I am not sure where the 4 additional boys come in or how to make the equations equal so that I can solve them. I really would appreciate your help!1 solutions Answer 112150 by Earlsdon(6291)   on 2008-08-19 20:49:20 (Show Source): You can put this solution on YOUR website!Ok, you got a good start! Let b = number of boys yesterday and (b+4) = the number of boys today and g = number of girls (This didn't change). Yesterday: g = 5b Today: g = 3(b+4) Since g = g, then; 5b = 3(b+4) Apply the distributive property on the right side. 5b = 3b+12 Subtract 3b from both sides. 2b = 12 Divide both sides by 2. b = 6 So, yesterday, there were 6 boys plus 5*(6) girls for a total of 36 children. Today, there are 6+4 = 10 boys and 3*10 = 30 girls for a total 40 children.
 Polynomials-and-rational-expressions/152518: g(2+h)=x to the third the instructor gave us x=(2+h) and the answer 8+12h+6h suared+h to the third i haven't been able to get that as my answer. here's what I have done: g(2+h)=x to the third g=(2+h)to the third g=(2+h)(2+h)(2+h) g=4+2h+2h+hsquared(2+h) g=8+4h+4h+2h+2h+2hsquared+h to the third g=8+12h+2hsquared+h to the third1 solutions Answer 112094 by Earlsdon(6291)   on 2008-08-19 14:03:25 (Show Source): You can put this solution on YOUR website! You are ok up to this point. which simplifies to Now you multiply this by Combining like-terms, you get: So...
 Geometry_Word_Problems/152487: Hi, How would I solve the following: Applications of Linear Equations Walt made an extra \$9000 last year from a part-time job. He invested part of the money at 9% and the rest at 8%. He made a total of \$770 in interest. How much was invested at 8%? Thank you for taking the time to help me. Sally1 solutions Answer 112076 by Earlsdon(6291)   on 2008-08-19 12:04:11 (Show Source): You can put this solution on YOUR website!G'day Sally; Let x = the amount invested at 8% and the remainder (\$9000-x) is invested at 9% The amount of interest earned on these amounts can be expressed as: x(0.08) This is amount earned at 8%. (\$9000-x)(0.09) This is the amount earned at 9% The sum (+) of these two amounts is given as \$770.00, so you can write the equation to solve for x, the amount invested at 8% (0.08)x + (0.09)(\$9000-x) = \$770 Simplify and solve for x. 0.08x + \$810 - 0.09x = \$770 Subtract \$810 from both sides. 0.08x-0.09x = -\$40 Combine the x's on the left side. -0.01x = -\$40 Finally, divide both sides by -0.01 to get x by itself. x = \$4000 So \$4000 was invested at 8% and \$9000-\$4000 = \$5000 was invested at 9% Let's check the solution: 0.08(\$4000) + 0.09(\$5000) = \$320 + \$450 = \$770 The total interest earned.
 logarithm/152475: 1 solutions Answer 112066 by Earlsdon(6291)   on 2008-08-19 11:23:55 (Show Source): You can put this solution on YOUR website!Solve for x: Apply the power rule to the first term on the left side: Now apply the quotient rule to the left side: Rewrite this in its exponential form: ---> Multiply both sides by (1-x) Expand the left side. Add to both sides. Factor the x on the right side. Divide both sides by Ths is the exact answer. If you want an approximate answer, then substitute to get:
 Expressions-with-variables/152490: What is the answer to F(x)=x3? I could not find where I could put a small 3 above the x but it means x to the third power.1 solutions Answer 112064 by Earlsdon(6291)   on 2008-08-19 10:58:57 (Show Source): You can put this solution on YOUR website!What is the answer to: ? The answer depends entirely upon the value of x! Did you forget to include that?
 Radicals/152491: This question is from textbook Intermediate Algebra Can someone help me with this problem. I am stuck on don't know which way to go. The problem is multiply sqrt of 27b sqrt of 3b^3k and simplify the result. Thanks for anyone that can help! 1 solutions Answer 112063 by Earlsdon(6291)   on 2008-08-19 10:56:28 (Show Source): You can put this solution on YOUR website!Simplify: ====
 Polynomials-and-rational-expressions/152481: How do you Divide this rational expression: x^2-9/4x+12(Divided by)x-3/6? I dont understannd this at all. Whats the answer?1 solutions Answer 112054 by Earlsdon(6291)   on 2008-08-19 09:59:11 (Show Source): You can put this solution on YOUR website!Divide: divided byDo the first fraction by factoring the numerator and the denominator: Cancel the indicated factors to leave you with: Now divide by the second fraction, but remember to change to multiplication and invert the second fraction. Cancel the indicated factors to leave you with: Finally, reduce this fraction to its lowest terms.
 Geometry_Word_Problems/152386: A, B, C, and D are distinct coplanar points, no 3 of which are collinear. If E is a point not in the plane of A, B, C, and D, how many distinct planes are determined by the 5 points? a. 4 b. 5 c. 6 d. 7 Which answer is correct and why?1 solutions Answer 112013 by Earlsdon(6291)   on 2008-08-18 19:27:00 (Show Source): You can put this solution on YOUR website!Think about this! Through any three non-collinear points, there is exactly one plane! The planes that you identify here must include the point E, so you can list all of the possible combinations of the points, A, B, C, D, with the point E. E,A,B E,A,C E,A,D E,B,C E,B,D E,C,D So it seems that there are 6 distinct planes determined by the five points if point E is to be included in each one.
 Exponents/152377: I am doing exponents in expanded form and have a question: In the number 1,203,487,386 when I start to expand this to (1 x 10-10)+(2 x 10-9)+ do I include the 0 or leave it out?)1 solutions Answer 112011 by Earlsdon(6291)   on 2008-08-18 19:11:28 (Show Source): You can put this solution on YOUR website!You should include the zero for completeness, and notice that you start at an exponent of 9: 1,203,487,386 = 1,000,000,000 = 200,000,000 = ------------------------- 3,000,000 = 400,000 = 80,000 = 7,000 = 300 = 80 = 6 = Recall that
 Angles/152385: This question is from textbook Geometry I'm not sure how to even begin this problem.1 solutions Answer 112010 by Earlsdon(6291)   on 2008-08-18 18:55:06 (Show Source): You can put this solution on YOUR website!Unfortunately, I don't have the math book from which your problem is taken.
 Exponents-negative-and-fractional/152382: This question is from textbook Algebra structure and method book 1 can you please help me answer: (((10x(2)-30x+20 over x(2)-1 1 solutions Answer 112009 by Earlsdon(6291)   on 2008-08-18 18:52:40 (Show Source): You can put this solution on YOUR website!Presumably you would like to simplify this fraction: Factor the numerator and the denominator. Cancel the indicated factors.
 Linear-systems/152381: hello. I am having difficulties with my summer math packet, I am really stuck on the problems that have to do with slope, one of these problems is to determine the slope of the line that passes through (5, 1) and (2, 7) so far, I have determined that it may be 6/-3, I used the y2-y1/x2-x1 formula, but I still sense it may be wrong. . I have even more difficulty when I have to use fractions with it such as (-1/2, -2) and (-3/2, 1), I have completely forgotten everything, and desperatly need help1 solutions Answer 112006 by Earlsdon(6291)   on 2008-08-18 18:39:44 (Show Source): You can put this solution on YOUR website!You have used the slope formula correctly: and substiuting the given points, you got: Now you should reduce this fraction to its lowest terms: Now let's look at the fractions.
 Radicals/152379: This question is from textbook Intermediate Algebra I am working on this problem and I just need to know if I did it right. I'm suppose to simplify each expression an if an expression can't be simplified, write "does not simplify. The problem is 2x^2+2x-12 over x^3+3x^2-4x-12 This is what I did Factored to 2(x^2+x-6) Factored to 2(x^2+3x-2x-6) Factored to 2(x(x+3)-2(x+3)) Factored to 2(x+3)(x-2) also common denominator 2x(x-2)+2*3(x-2) Simplified to 2x(x-2)+6(x-2) Factored to 2(x-2)(x+3) Second part denominator : Factored to x^2(x+3)-4(x+3) Factored to (x+3)(x^2-4) Factored to (x+3)(x+2)(x-2) also common denominator Expanded x(x+2)(x-2)+3(x+2)(x-2) also simplified Factored to (x+2)(x-2)(x+3) also simplified Now the answer I got was 2x(x-2)+6(x-2) over (x-2)(x+3)(x+2). Was this problem done correctly and is it simplified? Thanks for anyone who can check this.1 solutions Answer 112005 by Earlsdon(6291)   on 2008-08-18 18:23:33 (Show Source): You can put this solution on YOUR website!To answer your questions...NO! and NO! Let's look at the problem: Simplify: Let's do the numerator first: Factor the trinomial: = Your work in this step was ok! Now the denominator: Factor: = You correct here as well! Now we'll put 'em together: At this point, can you see the cancellation possibilities? =
 Mixture_Word_Problems/152357: Word Problems are so hard for me. I can do them with a calulator, but to write them out in algebriac terms and answering them, I am at a loss. Here is the word problem: Samantha needs 20 quarts of 50% antifreeze solution in her radiator. She plans to obtain this by nixing some pure antifreeze with an appropriate amount of 40% antifreeze solution. How many quarts of each should she use? I was thinking 40x . 50 = 20 or maybe 50x + (40 x 20) I am so new at math, and it is just confusing me to no end!I don't know how to write it, but normally if it's written out I can answer the problem if it's not too complicated. I would really appreciate any help on this.1 solutions Answer 112000 by Earlsdon(6291)   on 2008-08-18 15:56:13 (Show Source): You can put this solution on YOUR website!Some times, with mixture problems such as this one, it might be a little easier if you think in terms of just the antifreeze rather than the mixture. You are told that Samantha needs 20 quarts of 50% antifreeze. First, change the percentage to its decimal equavalent (50% = 50/100 = 0.5). Now 50% of 20 quarts of antifreeze mixture is really 0.5 (20) = 10 quarts of pure antifreeze. The amount of 40% antifreeze mixture to be added is (20-x) quarts, that is this is the amount, added to the x quarts of pure antifreeze to get the 20 quarts. Now let x = the amount of pure (100% = 1) antifreeze to be added to (20-x) quarts of 40% antifreeze mixture. The amount of 40% antifreeze mixture is 0.4(20-x) quarts of antifreeze. Now you can write an equation to solve for x, the number of quarts of pure antifreeze that Samantha needs. Perform the indicated multiplication. Combine the x's Subtract 8 from both sides. Finally, didvide both sides by 0.6 to get x by itself. or x = 3 1/3 So Samantha needs to mix 3 1/3 quarts of pure antifreeze with 20-x = 20-3 1/3 = 16 2/3 quarts of 40% antifreeze mixture to obtain 20 quarts of 50% antifreeze mixture..