x+y=-5 xy=6 x-y=(
问题描述:
x+y=-5 xy=6 x-y=(
答
(x-y)²=(x+y)²-4xy=(-5)²-4×6=1
则:
x-y=±1
x+y=-5 xy=6 x-y=(
(x-y)²=(x+y)²-4xy=(-5)²-4×6=1
则:
x-y=±1