Question

Quickly compute the following differences of squares. (a). 64^2 − 14^2 (b). 112^2 − 88^2 (c). 785^2 − 215^2

Answer 1

(a) 3900

(b) 4800

(c) 570000

Explanation:

We have given

(a)
`64^2-14^2`

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

So
`64^2-14^2=(64+14)(64-14)=3900`

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

`112^-88^2=(112+88)(112-88)=4800`

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

`785^2-215^2=(785+215)(785-215)=570000`