Expert: Sherman D. - 10/5/2007

Question
I am studying for the TExES Generalist 4-8 exam.  One of the practice questions is as follows:  Find the real roots of the equation 3x^2 - 45 + 22x.  The possible answers are: A. -5/9 and 9   B. 5/3 and 9   C. 5 and 9   D. -5 and -9.
Now, first of all, I KNOW this is NOT an equation since we don't have an equal sign.
Second, is there really ANY way to get the answer for this question?
Thank you for your insight.
Cindy

Answer
3x^2 - 45 + 22x
3x^2 + 22x - 45

using the quadratic formula

x = (-b ± sqrt(b^2 - 4ac))/(2a)

x = (-22 ± sqrt(22^2 - 4(3)(-45)))/(2(3))
x = (-22 ± sqrt(484 + 540))/6
x = (-22 ± sqrt(1024))/6
x = (-22 ± 32)/6
x = (-54/6) or (10/6)
x = -9 or (5/3)

so unless you typed something down wrong, the answer is none of the above.

also if you are wondering, the quadratic formula is the conclusion to completing the square.