Respuesta :
(r-1)^2= (r-1)(r-1)
Foil:
First: r*r=r^2
Outer: r*-1= -r
Inner: r*-1= -r
Last: -1*-1= 1
Put it together and simplify:
r^2-r-r+1
r^2-2r+1
Final answer: r^2-2r+1
Foil:
First: r*r=r^2
Outer: r*-1= -r
Inner: r*-1= -r
Last: -1*-1= 1
Put it together and simplify:
r^2-r-r+1
r^2-2r+1
Final answer: r^2-2r+1