题目内容
(1)已知x+y=9,xy=20,求y+1 |
x+1 |
x+1 |
y+1 |
a |
a-b |
a2 |
a2-2ab+b2 |
a |
a+b |
a2 |
a2-b2 |
y+1 |
x+1 |
x+1 |
y+1 |
(y+1)2+(x+1)2 |
(x+1)(y+1) |
(x+y)2-2xy+2(x+y)+2 |
xy+x+y+1 |
81-2×20+2×9+2 |
20+9+1 |
21 |
30 |
7 |
10 |
a(a-b)-a2 |
(a-b)2 |
a(a-b)-a2 |
(a+b)(a-b) |
-ab |
(a-b)2 |
-ab |
(a+b)(a-b) |
-ab |
(a-b)2 |
(a+b)(a-b) |
-ab |
a+b |
a-b |
2+1 |
2-1 |