Question

How do you factor and solve `25x^2 -9 =0`?

Answer 1

`x in {-3/5, 3/5}`

Explanation:

Using the difference of squares formula `a^2-b^2 = (a+b)(a-b)`, we have

`25x^2 - 9 = (5x)^2-3^2=(5x+3)(5x-3) = 0`

`=>5x+3 = 0 or 5x-3 = 0`

`=> 5x = -3 or 5x = 3`

`=> x = -3/5 or x = 3/5`