Tìm x, biết:
a) 3(1-4x)(x-1)+4(3x+2)(x+3) = 38
b) 5(2x+3)(x+2)-2(5x-4)(x-1) = 75
c) 2x^2 +3(x-1)(x+1) = 5x(x+1)
d) (8-5x)(x+2)+4(x-2)(x+1)+2(x-2)(x+2) = 0
e) 3x(4x-3)-2x(5-6x) = 0
g) 5(2x-3)+4x(x-2)+2x(3-2x) = 0
h) 3x(2-x)+2x(x-1) = 5x(x+3)
i) 3x(x+1)-5x(3-x)+6(x^2+2x+3) = 0
