Question

From the sum of 2y²+3yz,–y²–yz–z² and yz+2z² subtract the sum of 3y²–z²and –y²+yz+z²

Answer 1

$2y { }^{2} + yz + y {}^{2} - 3yz - z {}^{2} \\ 3y {}^{2} - yz - z {}^{2}$