若a+b=3,ab=-2,则(4a-5a-3ab)-(3a-6b+ab)=?
问题描述:
若a+b=3,ab=-2,则(4a-5a-3ab)-(3a-6b+ab)=?
答
原题可能是(4a-5b-3ab)-(3a-6b+ab)
=4a-5b-3ab-3a+6b-ab
=a+b-4ab
=3-4*(-2)
=3+8
=12