己知a+b=10,ab=-2,则(3a-2b)-(-5b+ab)的值为?
问题描述:
己知a+b=10,ab=-2,则(3a-2b)-(-5b+ab)的值为?
答
(3a-2b)-(-5b+ab)
=3a-2b+5b-ab
=3a+3b-ab
=3(a+b)-ab
=3X10-(-2)
=32