能简算的要简算. 2.87+5.6-0.87+4.4 1118
来源:学生作业帮 编辑:作业帮 分类:数学作业 时间:2024/10/04 16:43:11
能简算的要简算.
2.87+5.6-0.87+4.4 |
(1)2.87+5.6-0.87+4.4,
=(2.87-0.87)+(5.6+4.4), =2+10, =12; (2) 11 18×9- 11 18×6, =(9-6)× 11 18, =3× 11 18, = 11 6; (3)420÷7÷6, =420÷(6×7), =420÷42, =10; (4) 9 10-( 1 4+ 7 20)÷ 3 4, = 9 10- 3 5× 4 3, = 9 10- 4 5, = 1 10; (5) 1 2x+ 3 5x=4.4, ( 1 2+ 3 5)x=4.4, 11 10x=4.4, 11 10x÷ 11 10=4.4÷ 11 10, x=4.4× 10 11, x=4. |