已知x的平方 y的平方=26
解:已知:x^2 y^2=26、xy=3(x y)^2=x^2 y^2 2xy将已知代入,有:(x y)^2=26 2×3=26 6=32(x-y)^2=x^2 y^2-2xy将已知代入,有:(x-y)^2=26-2×3=26-6=20
解:已知:x^2 y^2=26、xy=3(x y)^2=x^2 y^2 2xy将已知代入,有:(x y)^2=26 2×3=26 6=32(x-y)^2=x^2 y^2-2xy将已知代入,有:(x-y)^2=26-2×3=26-6=20收起