Question

If p – 15 = 0 and 2x² + px + 25 = 0; find the values of x.

Answer 1

Given p – 15 = 0

`=>` p = 15

So, the given quadratic equation becomes

2x² + 15x + 25 = 0

`=>` 2x² + 10x + 5x + 25 = 0

`=>` 2x(x + 5) + 5(x + 5) = 0

`=>` (x + 5)(2x + 5) = 0

Either x + 5 = 0 or 2x + 5 = 0

`x = -5` or `x = (-5)/2`

∴ `x = (-5)/2, -5`