For the third problem, your work should look like this:
-b +/- √b^2 - 4ac / 2a ***** Plug in what you know ***********
-4 +/- √4^2 - 4(6)(-3) / 2(6) ***** Simplify ****************************
-4 +/- √4^2 + 72 / 12
-4 +/- √16 + 72 / 12
-4 +/- √88 / 12 (The -4 and 12 can be simplified since they are constants.)
-1 +/- √88 / 3 (√88 can be broken down)
√88 = 2√22 this means that you should now have:
-1 +/- 2√22 / 3
**** Now you have 2 different answers *************************************
If they want the exact answers, leave the answers as what you have. If they want an approximation as your answer, then simplify the problem further.
For exact answers:
answer 1: answer 2:
-1 + 2√22 / 3 -1 - 2√22 / 3
For completely simplified answers:
answer 1: answer 2:
-1 + 9.38 / 3 -1 - 9.38 / 3
8.38 / 3 -10.38 / 3
x = 2.79 x = -3.46
******* Note that the 9.38 is a rounded value. It is not the exact decimal because it was rounded to the nearest hundredths place. *****************
******* Also note that the first answer is rounded to the nearest tenths place. *********
