Question

(10分）(1)已知x=2-y=2+ 求：x²+xy+y²的值.

 (2)已知x=+1,求x+1-的值.

Answer

(1)x2+xy+y2

=(x2+2xy+y2)-xy

=(x+y)2-xy

=(2-+2+)2-(2-)(2+)

=16-1=15.

【解析】略