Question

It is an odd two digit number

The sum of its digits is 8
The sum of the squares of its digits is 50

Answer 1

⇔ Consider the first digit = a, and the second digit = b

≡ We know that:
⇔
`(a+b)=8`
⇔
`a^(2)+b^(2)=50`

≡ Solution:
⇒
`a^(2)+b^(2)=(a+b)^(2)-2ab`
⇒
`50=(8)^(2)-2ab`
⇒
`2ab=64-50`
⇒
`2ab=14`
⇒
`(a).(b)=7`

⇔ Cause a × b = 7, there are 2 option the value of ab that:
∴ a = 1, b = 7 → 17
∴ a = 7, b = 1 → 71

Answer 2

Could be either 17 or 71. The square of 7 is 49, square of 1 is 1. 49+1=50