Question

in a two digit number, the sum of the digits is equal to 9 and the product of the digits is equal to 20. what is the number ?​

Answer 1

Answer:

let x= once digit and y is tenth digit.

Then , number is 10y+x

So, if the digits interchange their places, then the number is 10x+y  

now,  

xy=20 ....(i)  

10y+x+9=10x+y

or 9x-9y=9

or x-y=1 ..(ii)  

From (i) and (ii) , we get  

x(x-1)=20=4X5

x=4 or 5 , but as x-y=1 , then x=5 and y=4  

The number is 45.

Answer 2

Step-by-step explanation:

45 is the answer for this question

4+5=9

4×5=20