配套习题- 消元法的综合应用 -【青果学院】

1/5单选题

难度：

1.用加减消元法解二元一次方程组时，必须使这两个方程中 ( )

A	某个未知数的系数是1
B	同一个未知数的系数相等
C	同一个未知数的系数互为相反数
D	某一个未知数的系数的绝对值相等

正确答案：RA==

5Yqg5YeP5raI5YWD5rOV77ya5Lik5Liq5LqM5YWD5LiA5qyh5pa556iL5Lit77yM5ZCM5LiA5pyq55+l5pWw55qE57O75pWw55u45Y+N5oiW55u4562J5pe277yM5oqK6L+Z5Lik5Liq5pa556iL55qE5Lik6L655YiG5Yir55u45Yqg5oiW55u45YeP77yM5LuO6ICM5raI5Y676L+Z5Liq5pyq55+l5pWw77yM5b6X5Yiw5LiA5Liq5LiA5YWD5LiA5qyh5pa556iL

2/5单选题

难度：

2.解方程组①

；②

，比较简便的方法是 ( )

A	均用代入法
B	均用加减法
C	①用代人法，②用加减法
D	①用加减法，②用代入法

正确答案：Qw==

5pa556iL57uE4pGg77yM5LiA5Liq5pa556iLLHnnmoTns7vmlbDkuLox77yM5pWF55So5Luj5YWl5raI5YWD5rOV6L6D566A5L6/77yb5pa556iL57uE4pGh77yM6YCa6L+H5Yqg5YeP5raI5YWD5rOV5raI5Y67eei+g+eugOS+v++8jOWPqumcgOimgeWwhuesrOS4gOS4quaWueeoi8OXM++8jOS4juesrOS6jOS4quaWueeoi+ebuOWKoOWNs+WPr+OAgg==

3/5单选题

难度：

3.若

=

，且x+y=21则x=____.y=____.

A	3,4
B	6,8
C	9,12
D	12,16

正确答案：Qw==

5LukPGltZyB3aWR0aD0yOCBoZWlnaHQ9NDcgc3JjPSJodHRwczovL3AyLnFpbmdndW8uY29tL0cxL00wMC83My83Mi9yQkFDRTFUSmtrSEFmUS02QUFBQmxwcHRqVVkwNDUucG5nIj49PGltZyB3aWR0aD0zOCBoZWlnaHQ9NDUgc3JjPSJodHRwczovL3AyLnFpbmdndW8uY29tL0cxL00wMC83My83Mi9yQkFDRTFUSmtrTGhtdnZkQUFBQm55UTg5bHM3MTYucG5nIj49a++8jOWNs3g9M2sseT00azviiLV4K3k9MjHvvIziiLQzays0az0yMSxrPTMs4oi0eD05LHk9MTI=

4/5单选题

难度：

4.已知a、b的值同时满足方程a+2b=8和2a+b=7,则a+b=（）

A	3
B	4
C	5
D	6

正确答案：Qw==

YSsyYj044pGg77yMMmErYj034pGh77yM55Sx4pGgK+KRoe+8jOW+l++8mjNhKzNiPTE1LOKItGErYj01

5/5单选题

难度：

5.若方程组

的解中x与y相等，则k的值为( )

A	3
B	20
C	10
D	0

正确答案：Qw==

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