(x+y)²+(X+y)+四分之一

(x+y)²+(X+y)+四分之一
(x+y)²+(X+y)+四分之一

(x+y)²+(X+y)+四分之一
(x+y)²+(X+y)+1/4
=【(x+y)+1/2】²
=（x+y+1/2）²

=(x+y)²+2×(x+y)×1/2+(1/2)²
=[(x+y)+1/2]²
=(x+y+1/2)²

(x+y)²+(X+y)+四分之一
=(x+y)²+2*(X+y)*0.5+0.5^2
=（x+y+0.5）^2

将x+y=a,1/2=b
(a+b)²=a²+2ab+b²
所以答案是(x+y+1/2)²

(x+y)²+(x+y)+1/4 =(x+y)²+2*(1/2)(x+y)+(1/2)²==(x+y+1/2)²

=（x+y）（x+y-1）+四分之一

(X+Y)^2+(X+Y)+1/4
=(X+Y)^2+2×1/2(X+Y)+(1/2)^2
=[(X+Y)+1/2]^2