解方程5x﹣4.2=6.312÷x=0.36+6.1x=30.4.
41+7= 43+4= 47+7= 48+8= 81+7= 83+4= 87+7= 88+8=
76+5= 78+3= 72+9= 77+7=
63+9= 65+7= 64+8= 67+9=
52+7= 56+7= 58+4= 59+6=
32+7= 35+6= 37+3= 39+8= 42+7= 45+6= 47+3= 49+8=