1. 写出下列各数的相反数:
(1)5;
(2)$\frac{4}{7}$;
(3)0;
(4)0.5;
(5)-2;
(6)$-\frac{4}{3}$;
(7)-5.1;
(8)$-1\frac{2}{3}$。
(1)5;
(2)$\frac{4}{7}$;
(3)0;
(4)0.5;
(5)-2;
(6)$-\frac{4}{3}$;
(7)-5.1;
(8)$-1\frac{2}{3}$。
答案:(1)$-5$
(2)$-\frac{4}{7}$
(3)$0$
(4)$-0.5$
(5)$2$
(6)$\frac{4}{3}$
(7)$5.1$
(8)$1\frac{2}{3}$
(2)$-\frac{4}{7}$
(3)$0$
(4)$-0.5$
(5)$2$
(6)$\frac{4}{3}$
(7)$5.1$
(8)$1\frac{2}{3}$
2. 化简下列各数:
(1) $-(-9)$;
(2) $+(-7.08)$;
(3) $-(+18)$;
(4) $+(+5)$;
(5) $-(-\dfrac{2}{5})$;
(6) $-(+0.4)$;
(7) $-[-(-10)]$;
(8) $+[-(-\dfrac{2}{3})]$;
(9) $-[-(+66)]$;
(10) $-\{+[-(-\dfrac{2}{5})]\}$。
(1) $-(-9)$;
(2) $+(-7.08)$;
(3) $-(+18)$;
(4) $+(+5)$;
(5) $-(-\dfrac{2}{5})$;
(6) $-(+0.4)$;
(7) $-[-(-10)]$;
(8) $+[-(-\dfrac{2}{3})]$;
(9) $-[-(+66)]$;
(10) $-\{+[-(-\dfrac{2}{5})]\}$。
答案:(1)$9$
(2)$-7.08$
(3)$-18$
(4)$5$
(5)$\frac{2}{5}$
(6)$-0.4$
(7)$-10$
(8)$\frac{2}{3}$
(9)$66$
(10)$-\frac{2}{5}$
(2)$-7.08$
(3)$-18$
(4)$5$
(5)$\frac{2}{5}$
(6)$-0.4$
(7)$-10$
(8)$\frac{2}{3}$
(9)$66$
(10)$-\frac{2}{5}$