Question

(x+1)^2+(x+1)(x-1)=????

Answer 1

(x+1)² + (x+1)(x-1) =

= x² + 2x + 1 + x² - 1 

= 2x² + 2x

Answer 2

$(x+1)^2+(x+1)(x-1) =\\ \\ = (x+1)\Big[(x+1)+(x-1)\Big] =\\ \\ = (x+1)(x+1+x-1) = \\ \\ = (x+1)(2x) =\\ \\ = 2x(x+1) =\\ \\= 2x^2+2x$