1) (x+10)^2+(x+6)^2=2x^2

2) -2х^2+3x-4=-x^2-x+(2-x^2)

3) -4x^2-4x=0

1) x^2 + 20x + 100 + x^2 + 12x + 36 = 2x^22x^2 - 2x^2 + 32x = - 13632x = - 136x= - 4,252) - 2x^2 + 3x - 4 + x^2 + x - 2 + x^2 =0- 2x^2 + 2x^2 + 4x - 6 =04x = 6x= 1,53) - 4x^2 - 4x = 0x^2 + x = 0x( x + 1) = 0x = 0x + 1 =0x = - 1