# Algebra problem solving for q

1. Jul 20, 2009

### jmb07

how do i go about solving for q in the equation:

(F x r x r)/k = (6.63E-6 -q)(q)

2. Jul 20, 2009

### RoyalCat

What are your knowns/unknowns and are there any additional equations?

I skimmed over your other thread, and you're trying to solve for q where the rest of the variables are known, right?

$$\frac{Fr^2}{k}=(6.63*10^{-6} -q)q$$
This is just a simple quadratic equation. Using factoring here obviously won't be useful since the numbers are a bit messy. Just arrange it to the general form ($$aq^2+bq+c=0$$) and solve for q, and remember any limits you may have on its value because of its physical properties.