помогите решить пример [tex]( \frac{1}{4}y^{2} + yz + 4z^{2}) ( \frac{1}{2} - 2z) [/tex]

(1/4у²+уz+4z²)(1/2-2z)=1/4y²*1/2-1/4y²*2z+yz*1/2-yz*2z+4z²*1/2-4z²*2z==1/8y²-1/2y²z+1/2yz-2yz²+2z²-6z³