Tìm x, biết: 5x(4x^2 – 2x + 1) – 2x(10x^2 – 5x + 2) = −36.
Tìm x, biết:
5x(4x2 – 2x + 1) – 2x(10x2 – 5x + 2) = −36.
Lời giải
5x(4x2 – 2x + 1) – 2x(10x2 – 5x + 2) = −36.
⇔ 20x3 – 10x + 5x – 20x3 + 10x – 4x + 36 = 0
⇔ x = −36.
Vậy x = −36.