完全平方公式的题

1.(__x/4_-1)²=(__x²/16_)-x/2+(_1__)
2.若x+y=10,xy=24
x²-xy+y²
=x²+2xy+y²-3xy
=(x+y)²-3xy
=10²-3*24
=100-72
=28

3.若x+y=10,xy=24
x²-xy+y²
=x²+2xy+y²-3xy
=(x+y)²-3xy
=10²-3*24
=100-72
=28

4.x+y=a,xy=b,
x²+y²
=x²+2xy+y²-2xy
=(x+y)²-2xy
=a²-2b

(x-y)²
=x²-2xy+y²
=x²+2xy+y²-4xy
=(x+y)²-4xy
=a²-4b

5.a²+b²+4a-6b+13=0
(a²+4a+4)+(b²-6b+9)=0
(a+2)²+(b-3)²=0
a+2=0,b-3=0
a=-2,b=3

1.(__x_-1)^2=(__x^2_)-x/2+(__1_)
2.若x+y=10,xy=24,求x^2-xy+y^2
(x+y)^2-3xy=28
3.若x+y=10,xy=24,求x^2-xy+y^2的值
同上
4.已知x+y=a,xy=b,用含a,b的代数式分别表示x^2+y^2和(x-y)^2
x^2+y^2=a^2-2b (x-y)^2=a^2-4b
5.已知a^2+b^2+4a-6b+13=0,求a,b的值
a=-2 b=3

1、1/2*x 1/4