9x^2-12x+4=0


-4x^2-12x+7=0

9x²-12x+4=0(3x-2)²=03x-2=03x=2x=2/3-4x²-12x+7=04x²+12x-7=0D=144+112=256x1=(-12-16)/8=-3,5x2=(-12+16)/8=0,5