Honore M.
asked • 08/10/18sum of digits of a 2-digit number is 7. the number obtained by interchanging the digits exceeds the original by 27. find the number
the sum of the digits of a 2-digit number is 7. The number obtained by interchanging the digits exceeds the original number by 27. Find the number.
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1 Expert Answer
Anita A. answered • 08/10/18
Tutor
4.9
(231)
Community College Math Instr; TX Secondary Mathematics Certification
Let x = the original ten's digit.
Let y = the original one's digit.
Then 10x + y is the value of the original 2-digit number, and 10y + x is the value of the interchanged 2-digit interchanged number.
The sum of the digits is 7: x + y = 7.
Interchanged number exceeds original number by 27.
10y + x = 10x + y + 27.
Us the substitution method to solve.
A2
Honore M.
oh my gush !! how can use substitution method in this??
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08/10/18
Anita A.
Since you are using one variable only, Let x = ten's digit, and (7-x) = one's digit.
10(7-x) + x = 10x + (7-x) + 27
A2
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08/10/18
Anita A.
Since x + y = 7, then y = (x-7)
A2
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08/10/18
Honore M.
i am so sorry cause ....... I solved this equation and the answer i found can not prove it right. Why?? Help me please
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08/14/18
Anita A.
x=2, y=5
Original number is 25, transposed number is 52.
25 + 27 = 52
Proving a result is done by substituting that result into the original equation to get a true statement.
10(7 - 2) + (2) = 10(2) + 7 - 2 + 27
10(5) +2 = 20 + 32
52 = 52 proved
aa
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08/23/18
Reeta S.
Thank you ma'am for the answer it helped me a lot!
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02/28/21
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Honore M.
08/23/18