Determine the solution set and mention what theorem you used to solve the problem.

a) |2x - 7| > or = 3

answer: ( - inf., 2] U [5, inf.)

theorem: ?

b) |3 - 5x| < or = 12

answer: [-9/5, 9]

theorem: ?

c) |6 - 4x| < or = 0

answer: (3,9)

theorem: ?

d) (3x^2 + 4) / (5 - x ) < 0

answer: ?

theorem: ?

f) |3x - 2| = |5 + 2x|

answer: {-3/5, 7, -3}

theorem: ?

help thanks! i have a feeling most are wrong