A two digit number is such that the product of its digit is 14. If 45 is added to the number, the digit interchange their place. Find the number?
Answers
Answered by
3
the nmbr is 27
product of 2 and 7 is 14
when we add 45 to it then it becomes 72
product of 2 and 7 is 14
when we add 45 to it then it becomes 72
Ayush062002:
right..... but I need process
Answered by
4
Hi.
Good Question...Keep Progressing...
Here is your answer---
Let the once digit in a number be y and tens digit be x
Thus, Number = 10x +y
According to the Question,
x * y = 14 --------------------------------------------eq(i)
Also,
10x +y +45 = 10y+x {As per as question}
10x - x +y - 10y = -45
9x - 9y = -45
9(x - y) = -45
Thus, x - y = -5
y = x + 5 ----------------------------------eq(2)
Putting eq(2) in the eq(1)
We get,
x * y = 14
x * (x +5) = 14
x ^2 + 5x = 14
x^2 +5x - 14 = 0
Splitting the middle term,
x^2 + 7x - 2x - 14 = 0
x( x - 7) - 2( x -7) = 0
(x - 7)(x - 2) = 0
By Zero Product Rule,
x - 7 = 0 x - 2 = 0
x = 7 x = 2
For, x = 7 in eq(i)
7 * y =14
y = 2
For, x = 2 in eq(i)
2 * y =14
y = 7
Thus, when x is 7 and y is 2,
Number = 10x + y
= 10(7) + 2
= 70 +2
= 72
Also, when x is 2 and y is 7,
Number = 10x + y
= 10(2) + 7
= 20 + 7
= 27
Thus, two digits number will be 72 or 27.
____________________________________
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Hope it helps.
Please mark this answer as Brainliest.
Have a nice day.
Good Question...Keep Progressing...
Here is your answer---
Let the once digit in a number be y and tens digit be x
Thus, Number = 10x +y
According to the Question,
x * y = 14 --------------------------------------------eq(i)
Also,
10x +y +45 = 10y+x {As per as question}
10x - x +y - 10y = -45
9x - 9y = -45
9(x - y) = -45
Thus, x - y = -5
y = x + 5 ----------------------------------eq(2)
Putting eq(2) in the eq(1)
We get,
x * y = 14
x * (x +5) = 14
x ^2 + 5x = 14
x^2 +5x - 14 = 0
Splitting the middle term,
x^2 + 7x - 2x - 14 = 0
x( x - 7) - 2( x -7) = 0
(x - 7)(x - 2) = 0
By Zero Product Rule,
x - 7 = 0 x - 2 = 0
x = 7 x = 2
For, x = 7 in eq(i)
7 * y =14
y = 2
For, x = 2 in eq(i)
2 * y =14
y = 7
Thus, when x is 7 and y is 2,
Number = 10x + y
= 10(7) + 2
= 70 +2
= 72
Also, when x is 2 and y is 7,
Number = 10x + y
= 10(2) + 7
= 20 + 7
= 27
Thus, two digits number will be 72 or 27.
____________________________________
____________________________________
Hope it helps.
Please mark this answer as Brainliest.
Have a nice day.
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