Tìm x biết: 2x(3x + 5) - x(6x - 1) = 33
Tìm x biết: 2x(3x + 5) – x(6x – 1) = 33.
2x(3x + 5) – x(6x – 1) = 33
⇔ 6x2 + 10x – 6x2 + x – 33 = 0
⇔ 11x = 33
⇔ x = 33 : 11
⇔ x = 3
Vậy x = 3.