Question

已知x=根号2+根号3，y=根号3-根号2，则x平方-xy+y平方等于多少

Answer 1

X²-xy+y²=(x+y)²-3xy=4*3-3=9

Answer 2

已知x=根号下2-根号下3,y=根号下2+根号下3,求x的平方-xy+y的平方
x² - xy + y²
= (x + y)² - 3xy
= (√2 - √3 + √2 + √3)² - 3(√2 - √3)(√2 + √3)
= (2√2)² - 3×(-1)
= 8 + 3
= 11