若ab=2,a+b=3,则(a-b)^2=(
问题描述:
若ab=2,a+b=3,则(a-b)^2=(
答
=(a+b)²-4ab
=9-8
=1
若ab=2,a+b=3,则(a-b)^2=(
=(a+b)²-4ab
=9-8
=1