数学题，急急急

更新时间2021-07-26 15:37:33

(1/2-y）^2-1/4（x+y）（x-y）

(1/2-y)²-(x+y)(x-y)/4

=1/4-y+y²-(x²/4-y²/4)

=1/4-y+y²-x²/4+y²/4

=5y²/4-x²/4-y+1/4

相关标签:数学