(7y-3z)-(8y-5z)=-y+2z(7y-3z)-(8y-5z)=7y-3z-8y+5z=(7y-8y)-(3z+5z)=_数学解答

(7y-3z)-(8y-5z)=-y+2z
(7y-3z)-(8y-5z)
=7y-3z-8y+5z
=(7y-8y)-(3z+5z)
=-y-8z
为什么是+2z?我觉得没变错,

人气：313 ℃　时间：2020-03-27 06:46:15

解答

3z-5z