Question

Solve:

`( x - 10)(1200/x + 2) = 1260` and x < 0

Answer 1

Given quadratic equation is `(x - 10)(1200/x + 2) = 1260`

`=> (x - 10)(1200/x + 2) = 1260`

`=>` (x – 10)(1200 + 2x) = 1260x

`=>` 1200x + 2x² – 12000 – 20x – 1260x

`=>` 2x² – 12000 – 80x = 0

`=>` x² – 40x – 6000 = 0

`=>` x² – 100x + 60x – 6000 = 0

`=>` (x = 100)(x + 60) = 0

`=>` x = 100 or x = – 60

But as x < 0, so x can't be positive.

Hence, x = – 60