Question

How do you multiply `(\frac { 2x } { 5} - 3) \cdot ( \frac { 2x } { 5} + 3)`?

Answer 1

`(4x^2)/25 - 9`

Explanation:

You need to cross multiple across the terms in parenthesis:

`((2x)/5 * (2x)/5) + ((2x)/5*3) + ((2x)/5*-3) + (3*-3) =>`

`(4x^2)/25 + (6x)/5 - (6x)/5 - 9 =>`

`(4x^2)/25 - 9`