Question

Rewrite the following differences of squares as a product of two integers. (a). 81 − 1 (b). 400 − 121

Answer 1

(a) 10×8

(b) 31×9

Explanation:

We have given that

(a) 81 - 1

We have to write this in form of product of two integers

We know the algebraic equation
`a^2-b^2=(a+b)(a-b)`

As 81 -1 can be written as
`9^2-1^2`

So
`9^2-1^2=(9+1)(9-1)=10* 8`

(b) We have given 400 - 121

We have to write this in form of product of two integers

We know the algebraic equation
`a^2-b^2=(a+b)(a-b)`

As 81 -1 can be written as
`{20}^2-{11}^2`

So
`{20}^2-{11}^1=(20+11)(20-11)=31* 9`