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# Recent problems solved by 'solver91311'

solver91311 answered: 16856 problems
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 Systems-of-equations/584955: solution to algebra problem n/2=n+1 please explain answer steps1 solutions Answer 372997 by solver91311(16868)   on 2012-03-09 18:48:02 (Show Source): You can put this solution on YOUR website! Multiply both sides by 2. Add -2n to both sides. Multiply both sides by -1. John My calculator said it, I believe it, that settles it
 Matrices-and-determiminant/584954: Find the value of the determinant |-6 -6| |b a|1 solutions Answer 372995 by solver91311(16868)   on 2012-03-09 18:46:08 (Show Source): You can put this solution on YOUR website! Product of the elements in the down diagonal: Product of the elements in the up diagonal: Down Diagonal minus the up diagonal: John My calculator said it, I believe it, that settles it
 Probability-and-statistics/584901: a number cube is rolled one time and the result is recorded. The same number cube is rolled a second time. What is the probablitiy that the sum of the rolls is greater than 7?1 solutions Answer 372973 by solver91311(16868)   on 2012-03-09 15:57:27 (Show Source): You can put this solution on YOUR website! There are 5 ways to make 8, 4 ways to make 9, 3 ways to make 10, 2 ways to make 11 and 1 way to make 12. 5 plus 4 plus 3 plus 2 plus 1 is 15 ways to achieve success out of 36 total outcomes. John My calculator said it, I believe it, that settles it
 Geometry_Word_Problems/584918: One evening 1500 concert tickets were sold. Tickets cost $20 for pavillion seats and$15 for lawn seats. Total receipts were \$27,500. How many tickets of each type were sold?1 solutions Answer 372972 by solver91311(16868)   on 2012-03-09 15:53:56 (Show Source): You can put this solution on YOUR website! Solve the 2X2 system. Substitution is probably the best method in this case. John My calculator said it, I believe it, that settles it
 Surface-area/584883: Prism A and prism B are similar. If prism A has length 5 feet and width 8 feet and prism B has length 7.5 feet, what is the width of prism B?1 solutions Answer 372971 by solver91311(16868)   on 2012-03-09 15:51:51 (Show Source): You can put this solution on YOUR website! Calculate , then calculate John My calculator said it, I believe it, that settles it
 Travel_Word_Problems/584916: A plane takes off traveling east at 175mph. A jet takes off from the same airport, also traveling east, 2 hours later at 315 mph. When will the jet overtake the airplane?1 solutions Answer 372968 by solver91311(16868)   on 2012-03-09 15:44:17 (Show Source): You can put this solution on YOUR website! In the first 2 hours, the (presumably non-jet) plane will have travelled 350 miles (2 hours times 175 mph). The jet is travelling 315 minus 175 = 140 mph faster. How long will it take to cover 350 miles at 140 mph? John My calculator said it, I believe it, that settles it
 Volume/584891: A rectangular prism has edges of 2, 3, and 4 cm. If each edge is increased by 50%, by what factor is the volume increased? Please show me how to do it1 solutions Answer 372967 by solver91311(16868)   on 2012-03-09 15:39:47 (Show Source): You can put this solution on YOUR website! Long (lots of arithmetic) way: Multiply the original length times width times height to get the original volume. Multiply each of the original dimensions by 1.5 to get the new dimensions. Multiply the new length times new width times new height to get the new volume. Divide the new volume by the old volume. Short way: Calculate John My calculator said it, I believe it, that settles it
 Miscellaneous_Word_Problems/584902: A nutrition class last 40 minutes. What frational part of an hour is the nutrition class?1 solutions Answer 372961 by solver91311(16868)   on 2012-03-09 15:24:10 (Show Source): You can put this solution on YOUR website! You will need to reduce the fraction. John My calculator said it, I believe it, that settles it
 Points-lines-and-rays/584911: Hi id like some help with this question here: A triangle has vertices A(11,1) B(3,6) and C(3,-4) Find an equation of the line that is parallel to AB and contains point C. I think it was (-2,-2)(3,-4)1 solutions Answer 372960 by solver91311(16868)   on 2012-03-09 15:22:19 (Show Source): You can put this solution on YOUR website! Parallel lines have identical slopes. Use the slope formula: where and are the coordinates of the given points A and B. Then use the point-slope form of an equation of a line: where are the coordinates of point C and is the slope calculated above. John My calculator said it, I believe it, that settles it
 Triangles/584906: a right isosceles triangle has legs of length 12cm. what is the length of its hypotenuse? Express your anwser in simples radical form1 solutions Answer 372959 by solver91311(16868)   on 2012-03-09 15:17:58 (Show Source): You can put this solution on YOUR website! The measure of the hypotenuse of an isosceles right triangle with legs that measure is John My calculator said it, I believe it, that settles it
 Polygons/584907: What is the sum of the measures of the interior angles in a 74-gon? 1 solutions Answer 372958 by solver91311(16868)   on 2012-03-09 15:15:26 (Show Source): You can put this solution on YOUR website! The sum of the measures of the interior angles of an -gon is given by degrees. Put in 74 for and do the arithmetic. John My calculator said it, I believe it, that settles it
 Sequences-and-series/584818: My grade in a certain math class is determined by three tests. My highest test score will count for 50% of my grade and my lowest for 20%; the "middle" test score will count for 30%. I must have a weighted average of 60 in order to pass the class. If I have already earned scores of 70 on my first two tests, what is the lowest score I can earn on the third test for which I will still pass the class?1 solutions Answer 372923 by solver91311(16868)   on 2012-03-09 13:07:20 (Show Source): You can put this solution on YOUR website! If you score greater than 70 on the third test, then obviously the weighted average will be greater than 70, hence the minimum score on the third test in order to reach a weighted average of 60 must be a score less than 70. That means that the top and middle scores will, in fact, be 70. So, your weighted average will be: Where is the score on the third test. Solve for Super Double Plus Extra Credit: True or False: If the scores on the first two tests had been 75, you could sleep in the day of the test. John My calculator said it, I believe it, that settles it
 Graphs/584821: Find the slope of the line through (5,8) and (-1,6)1 solutions Answer 372901 by solver91311(16868)   on 2012-03-09 11:48:31 (Show Source): You can put this solution on YOUR website! Use the slope formula: where and are the coordinates of the given points. John My calculator said it, I believe it, that settles it
 Functions/584823: is the function y=3x+4 a proportional function? 1 solutions Answer 372900 by solver91311(16868)   on 2012-03-09 11:47:24 (Show Source): You can put this solution on YOUR website! Since it is a linear function, it is a directly proportional function. John My calculator said it, I believe it, that settles it
 Travel_Word_Problems/584824: How much gas would it take to go 1100 miles in a Chevy aveo1 solutions Answer 372899 by solver91311(16868)   on 2012-03-09 11:45:41 (Show Source): You can put this solution on YOUR website! Same answer as I gave to the one you asked about the van. John My calculator said it, I believe it, that settles it
 percentage/584825: if i took a test and got 48 out of 51 questions correct what is the percentage of questions i got correct1 solutions Answer 372898 by solver91311(16868)   on 2012-03-09 11:44:16 (Show Source): You can put this solution on YOUR website! Divide 48 by 51. Move the decimal point two places to the right. Round to a level of precision appropriate to your intended use of the answer. If you answered 48 questions out of 51 correctly, the test probably didn't cover the subjects of grammar, punctuation, and capitalization. John My calculator said it, I believe it, that settles it
 Travel_Word_Problems/584819: How much gas would it take to go 144 miles in a van 1 solutions Answer 372897 by solver91311(16868)   on 2012-03-09 11:40:46 (Show Source): You can put this solution on YOUR website! 144 divided by the number of miles per gallon achieved by that particular van. The achieved mpg is effected by many factors: The size and type of engine, weight of the loaded vehicle, the material condition of the vehicle, including the engine and drive train, the inflation of the tires, the road conditions, the average speed over the trip, the particular driver's skill (or lack thereof), etc., ad infinitum, ad nauseum. In other words, even though there is no such thing as a stupid question asked by a student, you just got closer than anyone I have ever known. John My calculator said it, I believe it, that settles it
 Exponential-and-logarithmic-functions/584809: Natural logarithms question : In3x=81 solutions Answer 372896 by solver91311(16868)   on 2012-03-09 11:33:32 (Show Source): You can put this solution on YOUR website! so John My calculator said it, I believe it, that settles it
 Length-and-distance/584671: I am homeschooled and have only one instructor who I cannot get in touch with often since our schedules conflict and time zones are off. I really need help with this problem. Can you explain how to simplify? I can't find explanation anywhere in my online text for this and I know or at least think that length times width would give me an answer but don't know about converting yards and feet. The choices I have for answers never match what I come up with. Here is the question: A rectangular patio is 9 yd 2 ft long and 5 yd 2 ft wide. What is the perimeter of the patio in yards? Thank you!1 solutions Answer 372834 by solver91311(16868)   on 2012-03-08 23:41:22 (Show Source): You can put this solution on YOUR website! Length times width gives you the area. The perimeter is the total distance around the outside, so the length plus the width plus the length plus the width, or more simply: There are 3 feet in every yard. John My calculator said it, I believe it, that settles it
 Trigonometry-basics/584655: How do you verify identities? example: sin/1-cos+1-cos/sin=2csc1 solutions Answer 372833 by solver91311(16868)   on 2012-03-08 23:28:50 (Show Source): You can put this solution on YOUR website! Apply the LCD and add the two fractions: Apply the Pythagorean Identity to the numerator: Factor a 2 out of the numerator: Eliminate the factor common to both numerator and denominator: Sine is the reciprocal of Cosecant, so: John My calculator said it, I believe it, that settles it
 Geometry_proofs/584659: How do you prove that a/b is the same as b/a? Thanks! 1 solutions Answer 372831 by solver91311(16868)   on 2012-03-08 23:03:59 (Show Source): You can put this solution on YOUR website! You can't. In fact, you can easily prove that, in general, Let and let , then And, in fact, if and only if because 1 is the only real number equal to its own reciprocal. John My calculator said it, I believe it, that settles it
 Complex_Numbers/584346: (-1+3i)divided by (1+i)1 solutions Answer 372769 by solver91311(16868)   on 2012-03-08 16:13:17 (Show Source): You can put this solution on YOUR website! Multiply the fraction by 1 in the form of the conjugate of the denominator divided by itself: Use FOIL for the numerator and the fact that the product of a pair of binomial conjugates is the difference of two squares for the denominator. Don't forget that John My calculator said it, I believe it, that settles it
 Numeric_Fractions/584363: i do not understand this problem at all and i dont understand what im suppose to do on it... can you please explain to me? the problem is: A brick is 1 7/8 in. high Mortar that is 3/8 in. thick is spread on each row of bricks. How many rows of bricks are needed to reach the top of a 7 1/2-ft doorway? Please try to respond to this for me by tomorrow... my homework is due tomorrow and I really want to be able to know how to do this. Thank you so much for taking your time. 1 solutions Answer 372763 by solver91311(16868)   on 2012-03-08 15:16:54 (Show Source): You can put this solution on YOUR website! inches per row. , so seven and a half feet is 90 inches. How many times will inches fit into 90 inches? Divide 90 by 2.25. This assumes you lay the first course with no mortar beneath it (very dumb idea) or there is no layer of mortar on top of the last row of bricks. John My calculator said it, I believe it, that settles it
 Linear_Equations_And_Systems_Word_Problems/584362: how can i solve this 1.The sets P, Q and R are such that P ∩Q and P ∪Q ⊂R. a.) Draw a Venn diagram showing the sets, P,Q and R 1 solutions Answer 372759 by solver91311(16868)   on 2012-03-08 15:08:23 (Show Source): You can put this solution on YOUR website! Draw a rectangle. Draw two partially overlapping circles inside of the rectangle. Label the rectangle R and label one of the circles P and the other Q. Then P ∩ Q is the region where the two circles overlap and P ∪ Q is the area that comprises both circles including the overlap area. Both of these regions are fully contained in the universe region, R. John My calculator said it, I believe it, that settles it
 Rectangles/584349: a rectangle 15 cm wide has a perimeter of cm. what is the length of the rectangle1 solutions Answer 372756 by solver91311(16868)   on 2012-03-08 15:02:47 (Show Source): You can put this solution on YOUR website! So divide your perimeter by 2 and subtract the width. John My calculator said it, I believe it, that settles it
 Functions/584355: f=(-4y-7) find f=(y+h)1 solutions Answer 372753 by solver91311(16868)   on 2012-03-08 14:56:04 (Show Source): You can put this solution on YOUR website! I think you mean: Then which you can simplify to John My calculator said it, I believe it, that settles it
 Equations/584353: Find an equation of the line having given the slope and containing the given point. M=-6,(3,7) y=____1 solutions Answer 372752 by solver91311(16868)   on 2012-03-08 14:52:14 (Show Source): You can put this solution on YOUR website! Use the point-slope form of an equation of a line: where are the coordinates of the given point and is the given slope. John My calculator said it, I believe it, that settles it
 Equations/584351: Is pair of lines parallel, perpendicular, or neither? f(x)=-4x+7 g(x)=7x+31 solutions Answer 372750 by solver91311(16868)   on 2012-03-08 14:50:51 (Show Source): You can put this solution on YOUR website! Both are in slope-intercept form so that you can determine the slope of each by inspection. If the slopes are equal, the graphs are parallel (or possibly coincident). If the slopes are negative reciprocals, then the graphs are perpendicular. Otherwise, neither. John My calculator said it, I believe it, that settles it
 Probability-and-statistics/584299: Someone flips 15 biased coins once. The coins are weighted such that the probability of a head with any coin is 0.85. (a) What is the probability of getting exactly 14 heads? (b) What is the probability of getting at least 14 heads? (c) What is the probability of getting exactly 3 tails? Would I use the equation p= n!/(r!)(n-r)* p^r q^n - r 1 solutions Answer 372742 by solver91311(16868)   on 2012-03-08 13:36:09 (Show Source): You can put this solution on YOUR website! Yep: The probability of successes in trials where is the probability of success on any given trial is given by: Where is the number of combinations of things taken at a time and is calculated by For part (a) you want: Calculation Hint: For part (b) you want the probability of exactly 15 plus the result of part (a): Calculation Hint: and , hence: Part (c) is just straightforward fill in the numbers, get out the calculator, and crunch noting that the probability of a tail is 1 minus the probability of a head (save for that very, very tiny probability that the coin lands on its edge): On the other hand you can save yourself a boatload of arithmetic drugery if you open up a spreadsheet (Excel under Windows or Numbers on a Mac, they both work the same), pick a convenient empty cell, and type in: Part (a) =BINOMDIST(14,15,0.85,false) Part (b) =BINOMDIST(14,15,0.85,false) + BINOMDIST(15,15,0.85,false) Alternatively you could enter: =1 - BINOMDIST(13,15,0.85,true) Part (c) =BINOMDIST(3,15,0.15,false) John My calculator said it, I believe it, that settles it
 Graphs/584293: what does the graph for -2x + 3y = 1 look like?1 solutions Answer 372740 by solver91311(16868)   on 2012-03-08 13:03:40 (Show Source): You can put this solution on YOUR website! It is a straight line with a slope of that intersects the -axis at . John My calculator said it, I believe it, that settles it