《2025年暑假作业新疆青少年出版社七年级数学人教版》

1. 有下列方程:①$xy = 2$;②$3x = 4y$;③$x+\frac{1}{y}= 2$;④$y^{2}= 4x$;⑤$\frac{x}{2}= 3y - 1$;⑥$x + y - z = 1$.其中二元一次方程有 ()
A. 1 个
B. 2 个
C. 3 个
D. 4 个

答案： B

2. 下列各方程组中,属于二元一次方程组的是 ()
A. $\left\{\begin{array}{l}3x + 2y = 7,\\xy = 5.\end{array}\right.$
B. $\left\{\begin{array}{l}2x + y = 1,\\x + z = 2.\end{array}\right.$
C. $\left\{\begin{array}{l}\frac{x}{3}-\frac{y}{2}= 1,\\3x + 4y = 2.\end{array}\right.$
D. $\left\{\begin{array}{l}\frac{5}{x}+\frac{y}{3}= \frac{1}{2},\\x + 2y = 3.\end{array}\right.$

答案： C

3. 下列各组数中,不是二元一次方程$2x + y = 4$解的是 ()
A. $\left\{\begin{array}{l}x = 1,\\y = 2\end{array}\right.$
B. $\left\{\begin{array}{l}x = 2,\\y = 0\end{array}\right.$
C. $\left\{\begin{array}{l}x = 0.5,\\y = 3\end{array}\right.$
D. $\left\{\begin{array}{l}x = - 2,\\y = 4\end{array}\right.$

答案： D

4. 方程$5x + 2y = - 9与下列方程构成的方程组的解为\left\{\begin{array}{l}x = - 2,\\y= \frac{1}{2}\end{array}\right.$的是 ()
A. $x + 2y = 1$
B. $3x + 2y = - 8$
C. $5x + 4y = - 3$
D. $3x - 4y = - 8$

答案： D

5. 方程组$\left\{\begin{array}{l}ax + y = 0,\\x - by = 1\end{array}\right.的解是\left\{\begin{array}{l}x = 1,\\y = - 1,\end{array}\right.则a$,$b$的值为 ()
A. $\left\{\begin{array}{l}a = 0,\\b = 1\end{array}\right.$
B. $\left\{\begin{array}{l}a = 1,\\b = 0\end{array}\right.$
C. $\left\{\begin{array}{l}a = 1,\\b = 1\end{array}\right.$
D. $\left\{\begin{array}{l}a = 0,\\b = 0\end{array}\right.$

答案： D

6. 某校举行篮球赛,每场比赛都要分出胜负,每队胜一场得 2 分,负一场得 1 分.七年级(1)班在 16 场比赛中得 26 分.设该班胜$x$场,负$y$场,则根据题意,下列方程组中正确的是 ()
A. $\left\{\begin{array}{l}x + y = 26,\\x + 2y = 16.\end{array}\right.$
B. $\left\{\begin{array}{l}x + y = 26,\\2x + y = 16.\end{array}\right.$
C. $\left\{\begin{array}{l}x + y = 16,\\x + 2y = 26.\end{array}\right.$
D. $\left\{\begin{array}{l}x + y = 16,\\2x + y = 26.\end{array}\right.$

答案： C

7. 为提高学生学习兴趣,增强动手实践能力,某校为物理兴趣小组的同学购买了一根长度为 150 cm 的导线,将其全部截成 10 cm 和 20 cm 两种长度的导线用于实验操作(每种长度的导线至少一根),则截取方案共有 ()
A. 5 种
B. 6 种
C. 7 种
D. 8 种

答案： A

8. 若方程$x^{|m| - 2}+(m + 3)y^{2m - n}= 6是关于x$,$y$的二元一次方程,则$m + n = $______.

答案： 8