a/ 4x + 33 = -7
=> 4x = -7 - 33 = -40
=> x = \(\frac{-40}{4}=-10\)
Vậy x = -10
b/ 7(-x - 8) - 2(x + 5) = 12
=> -(7x) - 7.8 - 2x + (-2) . 5 = 12
=> -7x - 56 - 2x - 10 = 12
=> -7x - 2x = 12 + 10 + 56
=> -9x = 78
=> x = \(\frac{78}{-9}=\frac{-26}{3}\)
Vậy x = \(\frac{-26}{3}\)