Homework help: solve possibly using the quadr formula, completing the square or using factoring?

I'll complete the square:

-3t² + 4t + 5 = 0

We need the left side to be in the form of (t² + bt), so we'll subtract 5 from both sides then divide both sides by -3:

-3t² + 4t = -5

t² - (4/3)t = 5/3

Now that we have the correct form, to complete the square, follow these steps:

Start with t's coefficient: -4/3

half it: -2/3

square it: 4/9

Add that to both sides:

t² - (4/3)t + 4/9 = 5/3 + 4/9

Now we can factor the left side and simplify the right:

(t - 2/3)² = 15/9 + 4/9

(t - 2/3)² = 19/9

We can get the square root of both sides, then add 2/3 to both sides:

t - 2/3 = ±√(19) / 3

t = 2/3 ±√(19) / 3

or:

t = (2 ± √19) /. 3

https://www.google.com/search?q=-3t%5E2+%2B+4t+%2B...