2026年新课程学习指导七年级数学上册华师大版第38页答案
12. (1) $-10×(-\dfrac{3}{8})×(-3)×(-0.8).$
(2) $(-1020)×(-\dfrac{1020}{1021}).$

答案

(1) 9
(2) $1019\dfrac{1}{1021}$
13.(1)$(-8) × (-\frac{1}{6} - \frac{5}{12} + \frac{3}{10}) × 15.$
(2)$\frac{1}{7} × (-\frac{17}{4} - \frac{17}{3}) × (-\frac{7}{17}).$

答案

(1) 34
(2) $\dfrac{7}{12}$
14. $(-10) × (-3\dfrac{4}{7}) + (-9) × (-3\dfrac{4}{7}) + (-12) × 3\dfrac{4}{7}$

答案

14. 25
15. $\frac{7}{18} × (-72) + \frac{3}{4} × 72 - \frac{5}{6} × (-72) + (-\frac{7}{9}) × 72.$

答案

15. 30