Question

if A+B =16
A-B =8

Then A×A= ?

Answer 1

add the both given equations and we'll get
2A = 24 => A = 12
A × A = 12 × 12 = 144
Hope this helps you.

Answer 2

if A+B =16
A-B =8
________
2A=24(By cancelling +B and -B in above equations)

Therefore, A=12

Hence,A*A=12*12=144 is the answer.