2(x-4)(x-3)-(x+6)²=2(x²-4x-3x+12)-x²-12x-36=2x²-8x-6x+24-x²-12x-36=x²-26x-12
1)2*(x^2-3x-4x+12)-(x+6)^2 2)(2x^2-6x-8x+24)-(x^2+36+12x) 3)(2x^2-14x+24)-(x^2+36+12x)=x^2+2x+70