SOLUTION: solve each proportion then find another equlivent ratio x over 15 is equal to 12 over 90

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Question 1133139: solve each proportion then find another equlivent ratio x over 15 is equal to 12 over 90
Found 2 solutions by josgarithmetic, greenestamps:
Answer by josgarithmetic(39617) About Me  (Show Source):
You can put this solution on YOUR website!
15%2Fx=12%2F90

%2815%2Fx%29x=%2812%2F90%29x

15=%2812%2F90%29x

15%2890%2F12%29=x
15%283%2A30%29%2F%283%2A4%29=x
15%2830%2F4%29=x
15%2815%2F2%29=x
x=112%261%2F2


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ALTERNATIVE

x%2F15=90%2F12
x%2F15=%283%2A3%2A2%2A5%29%2F%283%2A4%29
%28x%2F%283%2A5%29%29=%283%2A5%29%2F2
x=%28%283%2A5%29%5E2%29%2F2
x=225%2F2
-
x=112%261%2F2

Answer by greenestamps(13200) About Me  (Show Source):
You can put this solution on YOUR website!


I'm sure the other tutor knows how to solve this kind of problem; however, they showed you two alternative methods for solving a DIFFERENT problem.

Of course the correct setup for solving the problem (or rather one possible correct setup) is

x%2F15+=+12%2F90

From there, there are many ways to find the solution.

you could "cross multiply" and do the arithmetic; or
you could simplify the fraction on the right (which in this case gives you the exact final answer); or
you could see that 90 is 6 times 15, which means 12 is 6 times x, making it easy to determine the value of x.