(-12)-(+8)+(-6)-(-5)=_____-21_____;读作:①_____负二十一_____;②_____负二分之四十二_____;
(+3.7)-(-2.1)-1.8+(-2.6)=_____1.4______;读作:①_____一点四_____;②____五分之七____;
(-12)-(+8)+(-6)-(-5)=_____-21_____;读作:①_____负二十一_____;②_____负二分之四十二_____;
(+3.7)-(-2.1)-1.8+(-2.6)=_____1.4______;读作:①_____一点四_____;②____五分之七____;