Question

How to solve- |-4(7-x)|=3

Answer 1

since |x| = x for x>=0 or -x for x<0

so, if -4(7-x) > 0, (x>7)
-4(7-x) = 3
-28 + 4x = 3
4x = 31
x=31/4
since 31/4 >=7, it works

or, if x<7,
-(-4(7-x)) = 3
4(7-x) = 3
28 - 4x = 3
-4x = -25
x = 25/4
since 25/4 < 7, it works