Absolute value is a number's distance away from 0. So, all answers are positive. -4/25 is 4/25's away from 0, so your answer is -4/25. To clarify: if you have the absolute value of ANY number, it will always be the positive version of itself.
(9x-15)/4=x /*4...... 9x-15=4x........ 5x=15........ x=3