Question

The tens digit of a certain number is five more than the units digit. The sum of the digits is 9. Find the number.

Answer 1

the tens digit = n
the units digit = n-5

n + n-5 = 9
2n = 9+5
2n = 14
n = 7  ←  the tens digit

the units digit = n-5 = 7 - 5 = 2

the number is 72

Answer 2

Answer: 72

Step-by-step explanation:

Let x represents the units digit of the number, then the value of tens digit will be $x+5$.

According to the question , we have the following equation:-

$\Rightarrow\ x+x+5=9\\\\\Rightarrow 2x+5=9$

Subtract 5 on both sides , we get

$2x=4$

Now, Divide 2 on the both sides , we get

$x=2$

Now, the unit digit of the number = 2

The tens digit of the number = 2+5=7

Then , the number will be : 72