Question

Solve using identity (91)2

Answer 1

We will use identity (iii) here,

(91)^2 = (100-9)^2  

= (100)^2 + (9)^2 - 2*100*9

= 10000+81-1800

= 10081-1800  

= 8281

Answer 2

Answer:

(90+1)²

(a+b)² = a²+ b²+ 2ab

(90+1) = (90)²+ (1)²+2×90×1

= 8,100 + 1 + 180

=8,281 (Answer)