1]the value of two digit number is3 times the sum of the two digit.if 9 is added to this two digit number,the new value will be 4 times the sum of the two digit.find the two digit number
PS.i need steps !!!THANK YOU
math problem
2007-10-08 5:03 am
回答 (1)
2007-10-08 5:15 am
✔ 最佳答案
let x be the ten-digit number and y be the unit-digit number.10x+y=3(x+y)
10x+y=3x+3y
7x-2y=0
x=2y/7----------(1)
10x+y+9=4(x+y)
10x+y+9=4x+4y
6x-3y+9=0-----------(2)
sub(1)into(2),
6(2y/7)-3y+9=0
12y/7-3y+9=0
-9y/7+9=0
y=7
suby=7 into (1)
x=2/7(7)=2
The two digit number is 27.
參考: ME
收錄日期: 2021-04-13 19:04:52
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20071007000051KK05532