作业帮 > 数学 > 作业

有理数简便计算乘法1.(-3/4)x(8-1 1/3-0.04)2.49 15/16 x (-8)3.(-370)x(-

来源:学生作业帮 编辑:搜狗做题网作业帮 分类:数学作业 时间:2024/04/30 16:05:40
有理数简便计算乘法
1.(-3/4)x(8-1 1/3-0.04)
2.49 15/16 x (-8)
3.(-370)x(-1/4)+0.25 x 24.5 + (-5 1/2)x(-2590)
有理数简便计算乘法1.(-3/4)x(8-1 1/3-0.04)2.49 15/16 x (-8)3.(-370)x(-
1.(-3/4)x(8-1 1/3-0.04)
=(-3/4)x(8-4/3-0.04)
=(-3/4)x8-(-3/4)x4/3-(-3/4)x0.04
=-6+1+0.03
=-4.97
2.49 15/16 x (-8)
=49x (-8)+15/16x (-8)
=-392-15/2
=-399-1/2
=-399 1/2
3.(-370)x(-1/4)+0.25 x 24.5 + (-5 1/2)x(-2590)
=(-370)x0.25+0.25 x 24.5 + (-5 1/2)x(-2590)
=(-370+24.5)x0.25 + (-5 1/2)x(-2590)
=(-345.5)x0.25 + (-5.5)x(-2590)
=-86.375+14245
=14158.625