I converted $5x^2 - 5x = 30$ into it's vertex form, and I just want to confirm my answer.
Here is what I did:
$5x^2 - 5x = 30$
$5x^2 - 5x - 30 = 0$
$5(x^2 - x - 6) = 0$
$5(x^2 - x) = 6$
$5(x^2 - x - (\frac{1}{2})^2) = 6 - (\frac{1}{2})^2$
$5(x^2 - x + \frac{1}{4}) = 6 + \frac{1}{4}$
$5(x^2 - x + \frac{1}{4}) = 6.25$
$5(x - \frac{1}{2})^2 - 6.25 = 0$
Is it right?
$\endgroup$1 Answer
$\begingroup$Mistake from
$$5(x^2-x-6)=0$$
to $$\color{green}{5}(x^2-x)=6$$
Also even though you wrote $-\left(\frac12\right)^2$, you actually meant $+\left(\frac12\right)^2$.
Quickest way to fix this is to get rid of the $5$ that I colored in green.
$$(x-\frac12)^2-6.25=0$$ is the vertex form.
$\endgroup$ 1
