Answer:
Explanation:
To find the vertex, we need to put this into vertex form, which is done by completing the square on the quadratic. Begin by moving the 8 over to he other side of the equals sign:
![3x^2-6x=-8](https://img.qammunity.org/2022/formulas/mathematics/college/nu1lxszx1ote98seyvjiew1pwe0q40lg84.png)
Now factor out the 3:
![3(x^2-2x)=-8](https://img.qammunity.org/2022/formulas/mathematics/college/mytqw91ip7ibpstlrhiq0pit0sajpc4lom.png)
Now take half the linear term, square it, and add it to both sides. Our linear term is 2. Half of 2 is 1, and 1 squared is 1:
![3(x^2-2x+1)=-8+3](https://img.qammunity.org/2022/formulas/mathematics/college/ex11t7q6hakkwi0sawbazukvr2f2w7gsc6.png)
We added a 3 on the right because 3 times the 1 we added in is 3. Cleaning that up a bit gives us the perfect square binomial on the left and -5 on the right:
![3(x-1)^2=-5](https://img.qammunity.org/2022/formulas/mathematics/college/lr8jqfxqp951aoi6db8prs91s8caqb2n0a.png)
and when we move the -5 back over by adding we have
and our vertex is seen to be (1, 5)