Question

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

Answer 1

Answer:

(a) 10×8

(b) 31×9

Step-by-step 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 $9^2-1^2=(9+1)(9-1)=10\times 8$

(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 ${20}^2-{11}^1=(20+11)(20-11)=31\times 9$