Question

please solve question 38

Answer 1

Wecolme to the concept of Algebra.   (25+20)^2 -( 25-20)^2

= (45)^2 - (5)^2

= (5×9)^2 - (5)^2.                                       We know that [ (ab)^2 = a^2 b^2] ,then

=( 5)^2  [ (9)^2  -1].  

= 25× 80= 2,000.

I hope it help you ✌️✌️. You also solve it by (a+b) (a-b) = a^2 - b^2 identity....