SOLUTION: The area of a rectangle is given by 12x^2+5x-2. One side has length 4x-1. Find the length of the other side

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Question 763453: The area of a rectangle is given by 12x^2+5x-2. One side has length 4x-1. Find the length of the other side
Answer by MathLover1(20849) About Me  (Show Source):
You can put this solution on YOUR website!


The area of a rectangle A=ab, where a and b are sides,
is given by A=12x%5E2%2B5x-2

given:
one side has length a=4x-1
A=12x%5E2%2B5x-2
solution:
ab=12x%5E2%2B5x-2.....plug in a=4x-1 and solve for b
%284x-1%29b=12x%5E2%2B5x-2
b=%2812x%5E2%2B5x-2%29%2F%284x-1%29........factor %2812x%5E2%2B5x-2%29: write 5x as -3x%2B8x
b=%2812x%5E2-3x%2B8x-2%29%2F%284x-1%29...group
b=%28%2812x%5E2-3x%29%2B%288x-2%29%29%2F%284x-1%29
b=%283x%284x-1%29%2B2%284x-1%29%29%2F%284x-1%29
b=%28%283x%2B2%29+%284x-1%29%29%2F%284x-1%29
b=%28%283x%2B2%29+cross%28%284x-1%29%29%29%2Fcross%28%284x-1%29%29

b=3x%2B2....the length of the other side