Tìm x, biết: a. x(x - 2012) - 2013x + 2012*2013 = 0; b. 12x(3 - 4x) + 7(4x - 3) = 0

tìm x
a. x(x-2012)-2013x+2012*2013=0
b. 12x(3-4x)+7(4x-3)=0
c. (x+2)(x^2-2x+4)+x(5-x)(x+5)=-17
d. 9x^2-4-2(3x-2)^2=0