作业帮0.39×9.8＋2×3.9怎样简算?
来源：学生作业帮助网 编辑：作业帮 时间：2024/05/06 03:56:46
0.39×9.8＋2×3.9怎样简算?
0.39×9.8＋2×3.9怎样简算?
0.39×9.8＋2×3.9怎样简算?
题目应该是：0.39×9.8+2×0.039这样的吧?
0.39×9.8+2×0.039
= 0.39×9.8+0.2×0.39
=0.39×(9.8+0.2)
=0.39×10
=3.9
0.39×9.8＋2×3.9
= 0.39×9.8+20×0.39
=0.39×(9.8+20)
=0.39×29.8（如果题目不变,后面凑不成10,无法简便运算啊!）
=0.39×(30-0.2)
=11.7-0.078
=11.622
0.39×9.8 2×3.9
= 3.9×0.98 2×3.9
=3.9×(0.98 2)
=3.9×2.98
=11.622
没打出来的是加号
望采纳 ， 谢谢！！！
0.39*9.8+2*3.9
=3.9*9.8+0.2*3.9
=3.9*（9.8+0.2）
=3.9*10
=39
“*”这个符号是乘号。
题出的有问题
=3.9*9.8*0.1+2*3.9
=3.9*0.98+2*3.9
=3.9*（0.98+2）
=3.9*2.98
=11.622