2u+3/4 = u-3
2u-u = -3-3/4
u = -12/4-3/4
u = -15/4
Note: -3 = -12/4 in fraction, we make the denominator into 4 because we want common denominator with the other number 3/4.
The answer above is wrong because he/she forgot that the 3 on the right is still negative. He/she used 12/4-3/4 and got 9/4 which is incorrect.
