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1. 计算:
(1) $2^{2}+(-2)^{2} × 2 - (-7.2) ÷ 0.8$;
(2) $\frac{2}{3} × (-5) + \frac{2}{3} × 1 - \frac{2}{3} ÷ (-\frac{1}{7})$;
(3) $[(-5)^{2} - 4^{2}] ÷ 3^{2} + (-2^{2}) × (-1)^{2}$;
(4) $-81 ÷ 2\frac{1}{4} × \left|-\frac{4}{9}\right| - 28 ÷ (-\frac{7}{4})$.
(1) $2^{2}+(-2)^{2} × 2 - (-7.2) ÷ 0.8$;
(2) $\frac{2}{3} × (-5) + \frac{2}{3} × 1 - \frac{2}{3} ÷ (-\frac{1}{7})$;
(3) $[(-5)^{2} - 4^{2}] ÷ 3^{2} + (-2^{2}) × (-1)^{2}$;
(4) $-81 ÷ 2\frac{1}{4} × \left|-\frac{4}{9}\right| - 28 ÷ (-\frac{7}{4})$.
答案
(1)21 (2)2 (3)-3 (4)0
2. 计算:
(1)$(-2)^{3}+(-3)×[(-4)^{2}+2]-(-3)^{2}÷(-2)$；
(2)$-(-1)^{2}+\left|-2×(-\dfrac{1}{4})\right|÷(-\dfrac{1}{2})-(-3)$；
(3)$-0.5^{2}+\dfrac{1}{4}-|-3^{2}-9|-(-1\dfrac{1}{2})^{3}×\dfrac{16}{27}$；
(4)$(-1)^{4}-\{\dfrac{3}{5}-[(\dfrac{1}{3})^{2}+0.4×(-1\dfrac{1}{2})]÷(-2)^{2}\}$.
(1)$(-2)^{3}+(-3)×[(-4)^{2}+2]-(-3)^{2}÷(-2)$；
(2)$-(-1)^{2}+\left|-2×(-\dfrac{1}{4})\right|÷(-\dfrac{1}{2})-(-3)$；
(3)$-0.5^{2}+\dfrac{1}{4}-|-3^{2}-9|-(-1\dfrac{1}{2})^{3}×\dfrac{16}{27}$；
(4)$(-1)^{4}-\{\dfrac{3}{5}-[(\dfrac{1}{3})^{2}+0.4×(-1\dfrac{1}{2})]÷(-2)^{2}\}$.
答案
(1)-57.5 (2)1 (3)-16 (4)$\frac{5}{18}$
