试卷数:5.7万套
练习册:1.1万册
用户量:55万
练习(P55)
1.(1)3--(-3)’=9-(-27)=9+27=36,
(2)-2*÷(-1)=-16÷1=-16.
(3)(-4)*+8-2’=16+8-8=2-8=-6
(4)(-1.5)x[7-{-2)-]
=(-1.5)x(7-4)
=-1.5x3
=-4.5.
2.(1)3x(-9)-(-28+14)÷7=3x(-9)-( -14)+7=-27-(-2)=-27+2
=-25.