# Math Help - Quadratic equations

I just encountered this question in the exam and I don't know what method to use here..

If the roots of the equation 2x^2+4x+7=0 are p and q , then the value of 1/p+1/q is :

The choices are:
A. -2
B. 7/2
C-4/7
D.7/4
E. none of the above.

Can somebody show me the step by step procedure how to solve this type of problem:
Any help would be appreciated..

2. Is this exam for a grade?

3. Originally Posted by Ackbeet
Is this exam for a grade?
I'm surprised that you don't know the context. He did say "the" exam after all!

But seriously, forks.

Until we can determine the nature of this problem, I'll just float this out there...

1/p + 1/q = (p + q)/(pq)

4. Originally Posted by riono3214
I just encountered this question in the exam and I don't know what method to use here..

If the roots of the equation 2x^2+4x+7=0 are p and q , then the value of 1/p+1/q is :

The choices are:
A. -2
B. 7/2
C-4/7
D.7/4
E. none of the above.

Can somebody show me the step by step procedure how to solve this type of problem:
Any help would be appreciated..
In this case, it is unclear whether you are still in the process of doing the exam, or if this is a question you encountered in an exam you have now FINISHED that you could not do. If it is the former, it's against the policy of MHF to do work for a student that constitutes part of their final grade. If it is the latter though, we can help you.

5. It's an finished entrance exam so it does not have anything to do with grades..

6. Originally Posted by riono3214
It's an entrance exam so it does not have anything to do with grades..

7. Originally Posted by riono3214
It's an finished entrance exam so it does not have anything to do with grades..
Actually, since you can't get a grade without entering the class, the entrance exam has EVERYTHING to do with grades...

Anyway, do you know how to use the Quadratic Formula? For any quadratic equation of the form $\displaystyle ax^2 + bx + c = 0$ the roots are $\displaystyle x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a}$.