Question

evaluate a2+ab-b2+5 when a=2 and b=3

Answer 1

So 22+23-32+5 ( 22+23=45 ) 45+32=77+5=82 So The Answer Is 82 . 
Just Add . 

Answer 2

a=2, b=3
if you have an algebra like 2a, it means a×2

a2+ab-b2+5
=2×2+2×3-3×2+5
=4+6-6+5
=4+5
=9

answer=9