1) -2*0.4^2-(-корень 2)^2 2(a+1)-(a+1)^2 3)

Question

1) -2*0.4^2-(-корень 2)^2

2(a+1)-(a+1)^2

3)

Answer 1

2(a+1)-(a+1)^2=(a+1)(2-a-1)=(a+1)(1-a)=1-a^2
x^2+x/x^2-1=x(x+1)/(x-1)(x+1)=x/(x-1)