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10. 计算:
(1) $-\dfrac{1}{2}-(+\dfrac{5}{4})-(-\dfrac{3}{2})+(-\dfrac{1}{4})$；
(2) $(-2)×(-4)-2^2÷(5-7)$；
(3) $\left|-2^2+4\right|-(\dfrac{1}{2}-\dfrac{1}{4}+\dfrac{1}{8})×(-24)$。
(1) $-\dfrac{1}{2}-(+\dfrac{5}{4})-(-\dfrac{3}{2})+(-\dfrac{1}{4})$；
(2) $(-2)×(-4)-2^2÷(5-7)$；
(3) $\left|-2^2+4\right|-(\dfrac{1}{2}-\dfrac{1}{4}+\dfrac{1}{8})×(-24)$。
答案
解：
(1) 原式$=-\dfrac{1}{2}-\dfrac{5}{4}+\dfrac{3}{2}-\dfrac{1}{4}$
$=(-\dfrac{1}{2}+\dfrac{3}{2})+(-\dfrac{5}{4}-\dfrac{1}{4})$
$=1-\dfrac{3}{2}$
$=-\dfrac{1}{2}$
(2) 原式$=(-2)×(-4)-4÷(-2)$
$=8-(-2)$
$=8+2$
$=10$
(3) 原式$=|-4+4|-[\dfrac{1}{2}×(-24)-\dfrac{1}{4}×(-24)+\dfrac{1}{8}×(-24)]$
$=0-(-12+6-3)$
$=0-(-9)$
$=9$
(1) 原式$=-\dfrac{1}{2}-\dfrac{5}{4}+\dfrac{3}{2}-\dfrac{1}{4}$
$=(-\dfrac{1}{2}+\dfrac{3}{2})+(-\dfrac{5}{4}-\dfrac{1}{4})$
$=1-\dfrac{3}{2}$
$=-\dfrac{1}{2}$
(2) 原式$=(-2)×(-4)-4÷(-2)$
$=8-(-2)$
$=8+2$
$=10$
(3) 原式$=|-4+4|-[\dfrac{1}{2}×(-24)-\dfrac{1}{4}×(-24)+\dfrac{1}{8}×(-24)]$
$=0-(-12+6-3)$
$=0-(-9)$
$=9$
