Tìm x: (x + 3)^2 + (x - 2)^2 - 2x^2 = 0

bài 1:tìm x:

a) (x+3)^2+(x-2)^2-2x^2=0

b)7x(x-2)-x+2=0

c)8x^3-12x^2+6x-1=0