已知:x-y=2,x的2次方-y的2次方=6,求x的2次方+y的2次方的值.

已知:x-y=2,x的2次方-y的2次方=6,求x的2次方+y的2次方的值.
2025-03-04 07:10:14
推荐回答(3个)
回答1:

x-y=2
x^2-y^2=(x+y)(x-y)=6
x+y=3
(x+y)^2+(x-y)^2=x^2+2xy+y^2+x^2-2xy+y^2
=2(x^2+y^2)=13
x^2+y^2=6.5

回答2:

x - y = 2

x^2 - y^2 = 6
(x + y)(x - y) = 6
x + y = 3

x = 5/2
y = 1/2

x^2 + y^2 = 26/4 = 13/2

回答3:

101/16