SOLUTION: Did I start out this problem correctly? Find the numerator:(-3x)/(5x-20)=(?)/(40-10x) I factored what I could and got this:(-3x)/[5(x-4)]=(?)/[-10(x-4)] I am not sure what

Algebra ->  Polynomials-and-rational-expressions -> SOLUTION: Did I start out this problem correctly? Find the numerator:(-3x)/(5x-20)=(?)/(40-10x) I factored what I could and got this:(-3x)/[5(x-4)]=(?)/[-10(x-4)] I am not sure what      Log On


   



Question 1056647: Did I start out this problem correctly?
Find the numerator:(-3x)/(5x-20)=(?)/(40-10x)
I factored what I could and got this:(-3x)/[5(x-4)]=(?)/[-10(x-4)]
I am not sure what to do beyond this point.

Found 2 solutions by josgarithmetic, MathTherapy:
Answer by josgarithmetic(39618) About Me  (Show Source):
You can put this solution on YOUR website!
Trust what you learned about fractions, regardless if with variable expressions or plainly written real numbers.

%28-3x%29%2F%285x-20%29=v%2F%2840-10x%29, and you want to know v.

%28%28-3x%29%2F%285x-20%29%29%2840-10x%29=v

v=%28-3x%29%2840-10x%29%2F%285x-20%29

v=%28-3x%29%2810%284-x%29%29%2F%285%28x-4%29%29
The negative factor,...

v=%28-1%29%283x%29%2810%284-x%29%29%2F%285%28x-4%29%29

v=%28-1%29%283x%29%282%284-x%29%29%2F%28x-4%29

v=3x%282%28x-4%29%29%2F%28x-4%29

v=3x%2A2

v=6x

Answer by MathTherapy(10552) About Me  (Show Source):
You can put this solution on YOUR website!

Did I start out this problem correctly?
Find the numerator:(-3x)/(5x-20)=(?)/(40-10x)
I factored what I could and got this:(-3x)/[5(x-4)]=(?)/[-10(x-4)]
I am not sure what to do beyond this point.
Where to go next!
Multiply the fraction: %28-+3x%29%2F5%28x+-+4%29, by %28-+2%29%2F%28-+2%29, to get: %28-+2%29%28-+3x%29%2F%28-+2%29%285%29%28x+-+4%29, and subsequently: