((hr-1)(r^2+hr)+(r^2+hr)):hr= (3h(h+r^2)+h(h+r^2)):4h=

Question

((hr-1)(r^2+hr)+(r^2+hr)):hr=
(3h(h+r^2)+h(h+r^2)):4h=

Answer 1

1).  ((hr-1)(r^2+hr)+(r^2+hr)):hr=(r^2+hr)(hr-1+1):hr=(r^2+hr)hr:hr=r^2+hr
2).  (3h(h+r^2)+h(h+r^2)):4h=(h+r^2)(3h+h):4h=(h+r^2)4h:4h=h+r^2