①6-(12)÷(-3) ②3×(-4)+(-28)÷7 ③4.7-(-8.9)-7.5+(-6)
问题描述:
①6-(12)÷(-3) ②3×(-4)+(-28)÷7 ③4.7-(-8.9)-7.5+(-6)
答
①6-(12)÷(-3)
=6-(-4)
=6+4
=10
②3×(-4)+(-28)÷7
=(-12)-28
=-(12+28)
=-40
③4.7-(-8.9)-7.5+(-6)
=4.7+8.9-7.5-6
=13.6-13.5
=0.1