作业帮 > 数学 > 作业

初一数学题对答案谢谢1.(-25)+13+|-7|―(-5);2.18-21÷(-7)×(-1/3);3.-3/4×(-

来源:学生作业帮 编辑:作业帮 分类:数学作业 时间:2024/05/24 05:55:11
初一数学题对答案谢谢
1.(-25)+13+|-7|―(-5);2.18-21÷(-7)×(-1/3);3.-3/4×(-8+1/3-1/2);4.-1的四次方-1/6×{2-(-3)²}
(1) -25+13-7+5
=-25-7+13+5
=-32+18
=-14
(2) 18-21×(-1/7)×(-1/3)
=18+3×(-1/3)
=18-1
=17
(3)-3/4×(-8+2/6-3/6)
=-3/4×(-8-1/6)
=-3/4×(-48/6-1/6)
=-3/4×(-49/6)
=49/8
(4)(-1)^4-1/6×(2-9)
=1-1/6×(-7)
=1+7/6
=13/6