Question

It is an odd two digit number

Answer 1

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

Answer 2

⇔ 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