1) 2х^2=3x
2x^2-3x=0
x(2x-3)=0
x=0 или 2х-7=0
2х=7
х=3,5
2)2=7x^2+2
2-7x^2-2=0
-7x^2=0
x=0
3)2x^2-8x+x-4=x^2-4
2x^2-7x-4-x^2+4=0
x^2-7x=0
x(x-7)=0
x=0 или x-7=0
x=7