Wednesday, September 5, 2012

What are the numerator and denominator of a fraction if them ratio is 3/4 ?If subtracting 8 from numerator and adding 8 to denominator the ratio...

The numbers are x and
y.


We'll write the first fraction x/y =
3/4.


x = 3y/4


We'll write
mathematically the second condition from
enunciation:


(x-8)/(y+8) =
1/6


y + 8 = 6(x-8)


We'll
remove the brackets:


y + 8 = 6x -
48


But x = 3y/4


y + 8 = 6*3y/4
- 48


y + 8 = 9y/2 - 48


We'll
multiply by 2 all over:


2y + 16 = 9y -
96


We'll move the terms in y to the left
side:


2y - 9y = -96 - 16


-7y =
-112


We'll divide by -7:


y =
16


We'll come back into the expression of
x:


x = 3*16/4


x =
3*4


x = 12


The
numbers are: x = 12 and y = 16.

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