mary and susan have 100 postcard in total.on susan's birthday,mary gives four over five of her postcard to susan.if susan has 85 postcards now.find the original number of postcards that mary has
来源:学生作业学帮网 编辑:学帮网 时间:2024/06/03 00:36:15
mary and susan have 100 postcard in total.on susan's birthday,mary gives four over five of her postcard to susan.if susan has 85 postcards now.find the original number of postcards that mary has
【参考答案】
susan现在有卡85张,则mary现在有卡100-85=15张.
设mary原有卡m张,susan原有卡100-m张
(100-m)+[(4/5)m]=85
100-m+(4/5)m=85
100-(1/5)m=85
(1/5)m=15
m=75
于是,mary原来的卡片是75张.
75
mary 有 a个card susan有b个card
a+b=100
4/5 a + b = 85
求a,有1/5 a = 15 => a=75
因此marry有75张卡。
望采纳,谢谢!
连接AC、BD交于O,连OE。由正方形ABCD有AC垂直BD于O,又PD垂直底面ABCD,所以PD垂直AC,故AC垂直平面PDB于O,即
全部展开
连接AC、BD交于O,连OE。由正方形ABCD有AC垂直BD于O,又PD垂直底面ABCD,所以PD垂直AC,故AC垂直平面PDB于O,即
收起
Susan and Mary 【填空】many books.A are have B has C have
mary and susan have 100 postcard in total.on susan's birthday,mary gives four over five of her postcard to susan.if susan has 85 postcards now.find the original number of postcards that mary has
How long have ;Tom and Mary -------[结婚]
jim and mary have/has a basketball
Hello,Linda!T____are my sisters,Mary and Susan根据句意和首字母意识完成下列各句.
Mary comes from the USA是什么意思?Tom and Mary have mary friends in China.是什么意思
Susan and her sister usually have lunch at home 的同义句是什么
mum can l invite susan _____(stay)with me and have a cup of coffe?
what are David and Mary doing?---They__(have dinner)
mary and linda have apples for lunch改为否定
But Linda and Mary ______(have)a balloon.
Mark and mary have three basketballs 该为一般疑问句
Mary and I have some basketball疑问句和否定句
Ann and Mary have baseballs改为一般疑问句
Mary and I have the same present.(改为同义句)
Tom and Mary have already climbed the Great Wall.{改为一般疑问句}Have Tom and Mary 空 the Great Wall
Mary and her friends are have breakfastMary and her friends are have breakfast改错
Mary is sixteen. Susan is fifteen. (同义句转换)