1.125+（-3又5分之2)+(-8分之1)+(-0.6)
=1+0.125-3-2/5-1/8-0.6
=1+0.125-3-0.4-0.125-0.6
=-3
7分之1+6分之5+(-7分之4)+(-2分之1)
=1/7+5/6-4/7-1/2
=-3/7+1/3
=-2/21