3 Answers

3x/2 - 4×/5 =15×/10 - 8×/10 = 7×/10

10 is the lowest common multiple, but you do not substract denominators. If you did, the answer would always be zero. 

    3x            4x

   ____   -    ____ 

      2              5

Find LCD > 10

     15x               8x

    _____   -    _______

       10                10

Answer:    7x

                ____

                  10

3x/2-4x/5

 STEP 1    find the LCF between denominators which is 2 & 5

and is 10 since 2 is able to go into 10 5times whiles 5 is also able to go into 10 2times and equat it to 0(zero)

STEP 2     change it from fraction into linear form by by multiply 3x/2 by 10 vice versa

STEP3      subtract 8x from 15x which is 7x =0

STEP4      divide through by 7 to find x and x is zero.

3x/2-4x/5=0

10*3x/2-10*4x/5=0

15x-8x=o

7x=0

7x/7=0/7

x=0