Adding and subtracting fractions with variables...?

Question

y= (x + 2) / 3 - (x - 1)/ 5 -1

I have a review packet to complete, and I can't remember how to simplify the problems. Do I cross multiply? Do I find a LCM or GCF? I really don't remember. Any help would be great.

(I know that the answer is x=1, I just can't remember how they got to that conclusion)

Is the case above the same situation as (x - 3) /25 = (x - 5) / 12

Thanks in advance!

Answer 1

6 hours and nobody told you to find the lowest common denominator?....15...{5(x+2) - 3(x-1) - 15} / 15 = y= {2x -2} / 15

Answer 2

y= (x + 2) / 3 - (x - 1)/ 5 -1 (yes, find lcd, which is 12)

y= (x + 2) / 3 - (x - 1)/ 4

y= 4(x + 2) / 12 - 3(x - 1)/12

y= 4x + 8 / 12 - 3x +3/12

y=4x+8-3x+3/12

y=7x+11/12

U can't solve for x unless you know y, so I'm not sure how they got x=1

(x - 3) /25 = (x - 5) / 12 (this one can be solved for x.  mult both sides by (12)(25)

12(x-3)=25(x-5)

12x-36=25x-125

-13x= - 89

x = 89/13 or 6 11/13