Form 2 maths
2008-03-25 9:17 pm
The sum of both digits in a two-digit number is 7. If the number is less than 11 times the tens digit by 3. Find the number.
回答 (2)
2008-03-25 9:20 pm
✔ 最佳答案
Let the tens digit be x, the units digit be y,x + y = 7---(1)
10x + y + 3 = 11x ---(2)
From (2),
x = y + 3 ---(3)
Substitute (3) into (1),
y + y + 3 = 7
2y = 4
y = 2 ---(4)
Substitute (4) into (3),
x = 2 + 3
x = 5
∴The number is 52.
2008-03-25 9:30 pm
Let A be the tens digit and B be singlar digit number
A + B = 7---(1)
B=7-A
10A+B = 11A-3---(2)
10A + 7-A=11A-3
7+9A = 11A-3
10=2A
A=5
B=2
So, the number is 52.
A + B = 7---(1)
B=7-A
10A+B = 11A-3---(2)
10A + 7-A=11A-3
7+9A = 11A-3
10=2A
A=5
B=2
So, the number is 52.
收錄日期: 2021-04-13 15:21:14
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https://hk.answers.yahoo.com/question/index?qid=20080325000051KK01261