配套习题- 加减消元法解二元一次方程组 -【青果学院】

1/5单选题

难度：

1.把方程3x-

y=

的左右两边同时扩大到原来的2倍，其结果为____.

A	6x-2y=3
B	6x-y=6
C	6x-y=3
D	2x-y=3

正确答案：Qw==

M3gtPGltZyB3aWR0aD0xNCBoZWlnaHQ9Mzcgc3JjPSJodHRwczovL3AyLnFpbmdndW8uY29tL0cxL00wMC83My83Mi9yQkFDRTFUSmtnM1RZT1RPQUFBQk5OM19Md3MzMzUucG5nIj55PTxpbWcgd2lkdGg9MjEgaGVpZ2h0PTM3IHNyYz0iaHR0cHM6Ly9wMS5xaW5nZ3VvLmNvbS9HMS9NMDAvQUEvQUUvckJBQ0ZGVEprZzZRSV9QLUFBQUJhQUZZVXJZNTE1LnBuZyI+LOWQhOmhuemDveaJqeWkpzLlgI3vvIzlvpc6IDZ4LXk9MyzpgIlD

2/5单选题

难度：

2.将方程组

中含有x项的系数都化为相等时为____

A
B
C
D

正确答案：QQ==

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

3/5单选题

难度：

3.用加减消元法解方程组

则①-②得( )

A	2y=1
B	5y=4
C	7y=5
D	-3y=-3

正确答案：Qw==

5YWI6LCD5pW06aG65bqP77yM5Li677yaPGltZyB3aWR0aD0xMzcgaGVpZ2h0PTYyIHNyYz0iaHR0cHM6Ly9wMi5xaW5nZ3VvLmNvbS9HMS9NMDAvM0YvM0IvckJBQ0oxVEpraHZqb3pqa0FBQUVXaXBKNUFjMDgxLnBuZyI+4pGgLeKRoeW+l++8mjd5PTU=

4/5单选题

难度：

4.解二元一次方程组的基本思想是( )

A	由一个未知数的值求另一个未知数的值
B	代入消元法或加减消元法
C	消元，化二元为一元
D	代入法

正确答案：Qw==

55CG6Kej5Luj5YWl5raI5YWD5rOV5ZKM5Yqg5YeP5raI5YWD5rOV6Kej5LqM5YWD5LiA5qyh5pa556iL57uE55qE5qC45b+D5oCd5oOz77yM5Y2z77ya5raI5YWD77yM5YyW5LqM5YWD5Li65LiA5YWD44CC

5/5单选题

难度：

5.用消元法解方程组

正确的方法是( )

A	①+②得2x=5
B	①+②得3x=12
C	①＋②得3x+7＝5
D	先将②变为x-3y=7③，①-③得x=-2

正确答案：RA==

PGltZyB3aWR0aD03MyBoZWlnaHQ9NDIgc3JjPSJodHRwczovL3AxLnFpbmdndW8uY29tL0cxL00wMC8zRi80Qy9yQkFDSjFUSnNxU0JraENoQUFBQ0RsSHFWcTA5ODMucG5nIj7vvJozeC0zeT0xMiszeS7mlYVBLkIuQ+Wdh+mUmQ==