(m-n) (n³-p³) - (n-p) (m³-n³)

(m-n) (n³-p³) - (n-p) (m³-n³)(m-n)*( n-p)*(n^2+np+p^2)- (n-p)*(m-n)*(m^2+mp+p^2)((n^2+np+p^2)-(m^2+mp+p^2)*((m-n)(n-p))(n^2+np+p^2-m^2-mp-p^2)*(mn+mp-n^2+np)