Tìm x, biết: (a) 3x+2=−10 (b) 3x^2−3x(2+x)=36

a) \(\begin{array}{l}3x + 2 = - 10\\x = - 4\end{array}\)

Vậy x = -4

b) \(\begin{array}{l}3{x^2} - 3x(2 + x) = 36\\x = - 6\end{array}\)

Vậy x = -6

c) \(\begin{array}{l}4{x^2} - 4x + 1 = 4\\{(2x - 1)^2} = {2^2}\\x = \frac{3}{2}(h)x = \frac{{ - 1}}{2}\end{array}\)

Vậy \(x = \frac{3}{2};x = \frac{{ - 1}}{2}\)

d) \(\begin{array}{l}{x^2} - {(x - 2)^2} = 36\\4x - 4 = 36\\x = 10\end{array}\)

Vậy x = 10