Garnet H. answered 02/05/13
Calculus, Physics, Stat, Linear Algebra, GRE, GMAT, SAT... Tutoring
you have an extra (-) there, so i assume you mean |4x+5| - 7 = 0
first step is to solve for the absolute expression...
|4x+5| = 7
now that we have this, imagine what this would mean: |y|=7
this means either y=7 or y=-7 (same as -y=7)
we use this same idea...
4x+5 = 7 or 4x+5 = -7
solving the first one, we get 4x=2 which leads to x = 1/2
and the second one gets us 4x=-12 which leads to x = -3