Question

Efectuar
(1+x)(x–1) – (4+x)(x–4)

Answer 1

$(1+x)(x-1)- (4+x)(x-4)\qquad Aplicamos \ propiedad \ distributiva \\ \\ (1*x-1*1+x*x-x*1)-(4*x-4*4+x*x-x*4)= \\ \\ (x-1+x^2-x)-(4x-16+x^2-4x) = \\ \\ (-1+x^2)-(-16+x^2) = \\ \\ -1+x^2+16-x^2= \boxed{15}$

Espero que te sirva, salu2!!!!

Answer 2

x+1)(x-1)=xal cuadrado-1
x+4)(x-4)=xal cuadrado-16
x2-1 -x2 +16=15