Question

(х+1)2-2(х+1)(х-10)+х2-1 срочно

Answer 1

$(x+1)^{2}-2(x+1)(x-10)+x^{2}-1 = x^{2}+2x+1+(-2x-2)(x-10)+x^{2}-1 =$$= x^{2}+2x+1-2x^{2}+20x-2x+20+x^{2}-1 = x^{2}+1-2x^{2}+20x+20x+x^{2}-1=$

$=x^{2}-2x^{2}+20x+20+x^{2}=0+20x+20=\bold{20x+20}$