Question

Evaluate the following using suitable identity 31*31-29*29

Answer 1

( 31 × 31) - ( 29 × 29)

= (31)^2 - (29)^2

= (31 + 29) (31 - 29)

= 60 × 2

= 120

Answer 2

a^2-b^2=(a+b)(a-b)

31^2-29^2

=(31+29)(31-29)

=60×2=120

hope this helps