I need help solving

30+0.006p^3=150-0.12p^2

Question

I need help solving 

30+0.006p^3=150-0.12p^2

zepdrix · Answer

Let's first change our decimals to fractions.
Then we can multiply through by the largest denominator to get rid of all the fractions.

It'll make it a lot easier to solve :D

So that p^3 term... hmm, the 6 appears to be in the thousandths place.
We can write it as $\dfrac{6}{1000}$.

If we do the same for the coefficient on the p^2 term, it becomes, $\dfrac{12}{100}$.

Giving us an equation of,$$\large 30+\frac{6}{1000}p^3=150-\frac{12}{100}p^2$$

zepdrix · Answer

From here we'll multiply both sides by 1000 since that is our largest denominator,
$$\large 30,000+6p^3=150,000-120p^2$$

anonymous · Answer

@zepdrix 120p^2+6p^3=120000 ... How do I solve p?

zepdrix · Answer

Hmm this doesn't factor nicely... thinkinggggg

zepdrix · Answer

@satellite73 @phi @Hero 
Hmm I can't quite figure this one out D:
I paged some of the smarty pants on here, maybe one of these guys will have an idea.

anonymous · Answer

lol ok

zepdrix · Answer

Woops, @Hero  when you make the substitution, it turns the first term into $y^{3/2}$, that's what i was getting a little confused on this one.