Question

Упростить:
(х-1)(х+1)+х(4-х)=?

Answer 1

(x-1)(x+1)+x(4-x)=$x^{2}$-1+4x-$x^{2}$=4x-1

Answer 2

$(x-1)(x+1)+x(4-x)=x^{2} -1+4x- x^{2} =4x-1$