配套习题- 用配方法解一元二次方程 -【青果学院】

1/5单选题

难度：

1.把方程

+3=4x配方，得（）

A	（x-2）²=7
B	（x+2）²=21
C	（x-2）²=1
D	（x+2）²=2

正确答案：Qw==

6Kej562U77ya4oi1IDxpbWcgd2lkdGg9MTcgaGVpZ2h0PTIxIHNyYz0iaHR0cHM6Ly9wMi5xaW5nZ3VvLmNvbS9HMS9NMDAvNzMvMUYvckJBQ0UxVElteVhoTW5Sb0FBQUJSS3VxR1c4NzIzLnBuZyI+KzM9NHg8YnI+4oi0PGltZyB3aWR0aD05NCBoZWlnaHQ9MjEgc3JjPSJodHRwczovL3AyLnFpbmdndW8uY29tL0cxL00wMC8zRS9BQi9yQkFDSmxUSW15WGhVZ3F0QUFBQjZNYnlEb285NTcucG5nIj48YnI+5omA5Lul6YWN5pa55b6X77yIeC0y77yJPHN1cD4yPC9zdXA+PTE8YnI+PGJyPuaVhemAiUM=

2/5单选题

难度：

2.将方程x

- 4x- 1=0的左边变成平方的形式是( )

A	(x- 2) =1
B	(x- 4) =1
C	(x- 2) =5
D	(x- 1) =4

正确答案：Qw==

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

3/5单选题

难度：

3.用配方法将二次三项式a²-4a+5变形，结果是（）

A	（a-2）²+1
B	（a+2）²-1
C	（a+2）²+1
D	（a-2）²-1

正确答案：QQ==

6Kej562U77yaYTxzdXA+Mjwvc3VwPi00YSs1PSBhPHN1cD4yPC9zdXA+LTRhKzQrMT3vvIhhLTLvvIk8c3VwPjI8L3N1cD4rMSA8YnI+5pWF6YCJQQ==

4/5单选题

难度：

4.不论x、y为什么实数，代数式x²+y²+2x-4y+7的值（）

A	总不小于2
B	总不小于7
C	可为任何实数
D	可能为负数

正确答案：QQ==

6Kej562U77ya4oi1eDxzdXA+Mjwvc3VwPit5PHN1cD4yPC9zdXA+KzJ4LTR5Kzc9PGltZyB3aWR0aD0xOTIgaGVpZ2h0PTIxIHNyYz0iaHR0cHM6Ly9wMi5xaW5nZ3VvLmNvbS9HMS9NMDAvNzMvMUYvckJBQ0UxVElteTdRV0ZzUUFBQURHdnBUbVNvMDQwLnBuZyI+PGJyPuKItOatpOW8j+WtkOeahOWAvOaAu+S4jeWwj+S6jjI8YnI+5pWF6YCJQQ==

5/5单选题

难度：

5.用配方法解方程x²+4x=10的根为（）

A	2±
B	-2±
C	-2+
D	2-

正确答案：Qg==

6Kej562U77ya4oi1IHg8c3VwPjI8L3N1cD4rNHg9MTA8YnI+4oi0IHg8c3VwPjI8L3N1cD4rNHgrND0xNDxicj48aW1nIHdpZHRoPTEyOCBoZWlnaHQ9NDIgc3JjPSJodHRwczovL3AxLnFpbmdndW8uY29tL0cxL00wMC8zRi80Ny9yQkFDSjFUSnJGYlJYc2EtQUFBQ3ZjM3VIcVkwNjAucG5nIj4s5omA5Lul5Y6f5pa556iL55qE5Lik5Liq5qC55Li6PGJyPlg9LTLCsTxpbWcgd2lkdGg9MzEgaGVpZ2h0PTIzIHNyYz0iaHR0cHM6Ly9wMS5xaW5nZ3VvLmNvbS9HMS9NMDAvM0YvMDYvckJBQ0psVEpyRmJ5dTZQbkFBQUJaTlVnX1JVNzc4LnBuZyI+PGJyPuaVhemAiUI8YnI+