Question

Solve x² + 3x - 18 = 0.O X =- 9 or x = 2X =O○ x = 6 or x = − 36 or x = 3x = 9 or x = -2

Answer 1

We can to note that the given quadratic polynomial on the left hand side can be rewritten as follows:

$x^2+3x-18=(x+6)(x-3)$

So, the given equation is equivalent to

$(x+6)(x-3)=0$

which implies to conditions:

$\begin{gathered} x+6=0 \\ or \\ x-3=0 \end{gathered}$

The former give us

$x=-6$

and the latter

$x=3$

Then, by comparing with the given options, the correct choice is the second one: x=-6 or x=3