Expert: Scott A Wilson - 9/10/2009

Question
i have had a complete brain lapse,
i am doing an algebra review in my trigonometry class and i can't figure out how to solve this last problem..

3x^2 + 9x + 10 = 6

if you could please help that'd be awesome

Answer
The first thing to do is to subtract 6 from both sides, so we have an equation equal to 0.
That gives 3x² + 9x + 4 = 0.

Next, note that a=3, b=9, and c=4 and use the quadratic equation,
y = (-b ± √(b²-4ac))/(2a).

Note that b²-4ac = 81 - 48 = 33, so the answers aren't simple numbers.

We said that a was 3, which makes 2a into 6, so the answer is (-9 ±√33)/6.