4x²-6x-(y-2)(y+1)=04x²-6x-(y²+y-2y-2)=04x²-6x-y²+y+2=04(x²-3/2x)-(y²-y)+2=04(x²-3/2x+9/16)-9/4-(y²-y+1/4)+1/4+2=04(x-3/4)²-(y-1/2)²=0[2(x-3/4)+(y...