1. 方程$6x+7=2x-5$的解是
x=-3
.答案:1. $x=-3$
2. 若代数式$6x - 5$与$-\dfrac{1}{2}$互为倒数,则$x$为(
A.$-1$
B.$-\dfrac{1}{2}$
C.$1$
D.$\dfrac{1}{2}$
D
)A.$-1$
B.$-\dfrac{1}{2}$
C.$1$
D.$\dfrac{1}{2}$
答案:2. D
3. 方程$2m + x = 1$与方程$3x - 1 = 2x + 1$的解相同,则$m$的值为(
A.0
B.1
C.$-2$
D.$-\dfrac{1}{2}$
D
)A.0
B.1
C.$-2$
D.$-\dfrac{1}{2}$
答案:3. D
4. 已知$x=-2$是方程$2x+2m-4=0$的一个解,则$m$的值是(
A.4
B.$-4$
C.0
D.2
A
)A.4
B.$-4$
C.0
D.2
答案:4. A
5. 解方程$2x+5=4$,移项正确的是 (
A.$2x=1$
B.$2x=9$
C.$2x=5-4$
D.$2x=4-5$
D
)A.$2x=1$
B.$2x=9$
C.$2x=5-4$
D.$2x=4-5$
答案:5. D
6. 小华同学在解方程$5x - 1 = (\ )x + 11$时,把“$(\ )$”处的数字看成了它的相反数,解得$x = 2$,则该方程正确的解应为(
A.$x = -1$
B.$x = 1$
C.$x = -3$
D.$x = 3$
D
)A.$x = -1$
B.$x = 1$
C.$x = -3$
D.$x = 3$
答案:6. D
7. 若代数式$8x - 7$与$6 - 2x$的值互为相反数,则$x$的值等于(
A.$-\dfrac{13}{10}$
B.$-\dfrac{1}{6}$
C.$\dfrac{1}{6}$
D.$\dfrac{13}{10}$
C
)A.$-\dfrac{13}{10}$
B.$-\dfrac{1}{6}$
C.$\dfrac{1}{6}$
D.$\dfrac{13}{10}$
答案:7. C
8. 解下列方程:
(1) $4x - 2 = 2x + 8$;
(2) $2x + 5 = 5x - 7$;
(3) $1 - \frac{6}{5}x = 3 + \frac{7}{10}$;
(4) $0.21x - 0.8 = 0.5 + 0.41x$。
(1) $4x - 2 = 2x + 8$;
(2) $2x + 5 = 5x - 7$;
(3) $1 - \frac{6}{5}x = 3 + \frac{7}{10}$;
(4) $0.21x - 0.8 = 0.5 + 0.41x$。
答案:8. (1) $x = 5$;(2) $x=4$;(3) $x=-\frac{9}{4}$;(4) $x=-6.5$