文具店有钢笔和毛笔共69支,每支钢笔7.5元,每支毛笔18元,全部卖掉后,毛笔比钢笔多卖120元,毛笔有几支要用方程解!我急用,对了还加++++++++++++++++++++++++++++++++++++++++++++++++++++++
来源:学生作业帮助网 编辑:作业帮 时间:2024/07/19 06:14:24
![文具店有钢笔和毛笔共69支,每支钢笔7.5元,每支毛笔18元,全部卖掉后,毛笔比钢笔多卖120元,毛笔有几支要用方程解!我急用,对了还加++++++++++++++++++++++++++++++++++++++++++++++++++++++](/uploads/image/z/929521-1-1.jpg?t=%E6%96%87%E5%85%B7%E5%BA%97%E6%9C%89%E9%92%A2%E7%AC%94%E5%92%8C%E6%AF%9B%E7%AC%94%E5%85%B169%E6%94%AF%2C%E6%AF%8F%E6%94%AF%E9%92%A2%E7%AC%947.5%E5%85%83%2C%E6%AF%8F%E6%94%AF%E6%AF%9B%E7%AC%9418%E5%85%83%2C%E5%85%A8%E9%83%A8%E5%8D%96%E6%8E%89%E5%90%8E%2C%E6%AF%9B%E7%AC%94%E6%AF%94%E9%92%A2%E7%AC%94%E5%A4%9A%E5%8D%96120%E5%85%83%2C%E6%AF%9B%E7%AC%94%E6%9C%89%E5%87%A0%E6%94%AF%E8%A6%81%E7%94%A8%E6%96%B9%E7%A8%8B%E8%A7%A3%21%E6%88%91%E6%80%A5%E7%94%A8%2C%E5%AF%B9%E4%BA%86%E8%BF%98%E5%8A%A0%2B%2B%2B%2B%2B%2B%2B%2B%2B%2B%2B%2B%2B%2B%2B%2B%2B%2B%2B%2B%2B%2B%2B%2B%2B%2B%2B%2B%2B%2B%2B%2B%2B%2B%2B%2B%2B%2B%2B%2B%2B%2B%2B%2B%2B%2B%2B%2B%2B%2B%2B%2B%2B%2B)
文具店有钢笔和毛笔共69支,每支钢笔7.5元,每支毛笔18元,全部卖掉后,毛笔比钢笔多卖120元,毛笔有几支要用方程解!我急用,对了还加++++++++++++++++++++++++++++++++++++++++++++++++++++++
文具店有钢笔和毛笔共69支,每支钢笔7.5元,每支毛笔18元,全部卖掉后,毛笔比钢笔多卖120元,毛笔有几支
要用方程解!
我急用,对了还加++++++++++++++++++++++++++++++++++++++++++++++++++++++
文具店有钢笔和毛笔共69支,每支钢笔7.5元,每支毛笔18元,全部卖掉后,毛笔比钢笔多卖120元,毛笔有几支要用方程解!我急用,对了还加++++++++++++++++++++++++++++++++++++++++++++++++++++++
设毛笔有X支,则钢笔有(69-X)支,根据题意,可以列出以下方程:
18X-(69-X)×7.5=120
18X-517.5+7.5X=120
25.5X=637.5
X=25
方法一:
设毛笔有X支,则钢笔有(69-X)支,根据题意,可以列出以下方程:
18X-7.5(69-X)=120
解方程得X=25,所以毛笔有25支。
方法二:
设毛笔有x支,则钢笔有(69-x)支
(69-x)*7.5+120=18x
69*7.5-7.5x+120=18x
517.5...
全部展开
方法一:
设毛笔有X支,则钢笔有(69-X)支,根据题意,可以列出以下方程:
18X-7.5(69-X)=120
解方程得X=25,所以毛笔有25支。
方法二:
设毛笔有x支,则钢笔有(69-x)支
(69-x)*7.5+120=18x
69*7.5-7.5x+120=18x
517.5+120=18x+7.5x
637.5 =25.5x
x=637.5/25.5
x=25
答:毛笔有25支!
收起
设毛笔X只,钢笔Y只,X+Y=18,18X-7.5Y=120,解之得X=10,Y=8,毛笔10只
X=25
设 毛笔有X支,钢笔有(69-x)支,18x-7.5(69-x)=120
解得x=25 答:毛笔有25支
设钢笔X,毛笔Y
X Y=69
18y-7.5x=120
X=25
Y=44