A two digit number is such that the product of the digits is 14. When 45 is added to the
number then the digits are reversed. Find the number.
Answers
Answer:
47 I the answer
Step-by-step explanation:
it's help you
Answer :
- The number is 27.
Given :
- A two digit number is such that the product of the digits is 14.
- When 45 is added to the number then the digits are reversed
To find :
- The number
Solution :
- Let the units digits be x
- Let the tens digits be y
Given, A two digit number is such that the product of the digits is 14 then,
- xy = 14
⟹ xy = 14
⟹ y = 14/x
y = 14/x ..... equation (1)
And also Given that , when 45 is added to the number then the digits are reversed so,
- (10y + x) + 45 = 10x + y
⟹ (10y + x) + 45 = 10x + y
⟹ 9y - 9x = -45
⟹ y - x = 5
y - x = 5 ..... equation (2)
Now , from equation (1) and equation (2) we get,
⟹ y = 14/x + y - x = 5
⟹ 14/x - x = -5
⟹ 14 - x² / x = -5
⟹ 14 - x² = - 5
⟹ x² - 5x - 14 = 0
⟹ x² - (7 - 2)x - 14 = 0
⟹ x² - 7x + 2x - 14 = 0
⟹ x(x - 7) + 2(x - 7) = 0
⟹ (x - 7) (x + 2) = 0
⟹ x - 7 = 0 or x + 2 = 0
⟹ x = 7 or x = -2
So , digit cannot be negative.
Now, putting the value of x = 7 in equation (1) we get,
⟹ y = 14/x
⟹ y = 14/7
⟹ y = 2
- y = 2
- x = 7
Now , we have to find the number :
⟹ 10 × y + x
⟹ 10 × 2 + 7
⟹ 20 + 7
⟹ 27
Hence , The number is 27.