a) /2x + 1/ = 4
=> 2x + 1 = 4 hoặc 2x + 1 = -4
Nếu 2x + 1 = 4
=> x = \(\frac{3}{2}\)
Nếu 2x + 1 = -4
=> x = \(\frac{-5}{2}\)
Vậy x = \(\frac{3}{2}\) hoặc x = \(\frac{-5}{2}\)
b) 5x - 3 = 4x -7
=> ( 5x - 3 ) - ( 4x - 7 ) = 0
=> 5x - 3 - 4x + 7 = 0
=> ( 5x - 4x ) - ( 3 - 7 ) = 0
=> x + 4 = 0
=> x = -4
Vậy x = -4