Question

计算有理数的加减法:(请写出过程)谢 1.(-0.7)+(-0.4)+1+(-0.3)+0.5 2.(+15)+(-20

Answer 1

(-0.7)+(-0.4)+1+(-0.3)+0.5

=-0.7-0.4+1+1-0.3+0.5

=-1.1+2-0.3+0.5

=0.9-0.3+0.5

=0.6+0.5

=1.1