—xy的平方加9x等于多少?
问题描述:
—xy的平方加9x等于多少?
答
-xy²+9x
=9x-xy²
=(9-y²)x
=(3+y)(3-y)x
—xy的平方加9x等于多少?
-xy²+9x
=9x-xy²
=(9-y²)x
=(3+y)(3-y)x