Question

-efectuar : E=(x+y+z+w)(x-y+z-w)

Answer 1

E = (x + y + z + w)(x – y + z – w)
E = (x + y + z + w)(x + z – y – w)
E = [(x + z) + (y + w)][(x + z) –( y + w)]
E= (x+z)² - (y+w)²
E=(x²+2xz+z²)-(y²+2yz+w²)
E=x²+2xz+z²-y²-2yz-w²