6(x+1)²+2(x-1)(x²+x+1)-2(x+1)³ =26

6(x+1)²+2(x-1)(x²+x+1)-2(x+1)³-26=06(x²+2x+1)+2(x-1)(x²+x+1)-2(x³+3x²+3x+1)-26=0(6x²+12x+6)+(2x-2)(x²+x+1)-(2x³+6²+6x+2)-26=0(6x²+12x+6)+(2x³-2)-(2x³+6x²+6x+2)-26=0(6x²+12x+6+2x³-2-2x³-6x²-6x-2-26=06x-24=06x=24x=24÷6x=4