Solve for x in the proportion:

Question

anonymous · Answer

$$\frac{ 2x }{ 16x + 30 }$$ 
= $$\frac{ -1 }{ x }$$

johnweldon1993 · Answer

What do you get when you do this one?

anonymous · Answer

2x^2 = -16x - 30 <--- This is all I know to do.

johnweldon1993 · Answer

That is correct.....do me a favor and add 16x and 30 to both sides...

You'll then have

$$\large 2x^2 + 16x + 30 = 0$$

Look familiar?

anonymous · Answer

So certain problems have to go to = 0? and some don't?

johnweldon1993 · Answer

Well no...but in the form I put it in...it is a quadratic equation....can be solved by factoring...makes it easier than guess and check

anonymous · Answer

Ahh okay. Let me find the factors of that.

anonymous · Answer

2(x + 3)(x + 5)

anonymous · Answer

Then to cancel out to 0, x + 3 would be -3 and x + 5 would be -5?
Which is the x's? -3 and -5

johnweldon1993 · Answer

That would be correct! You can even check those answers by plugging then into the original equation

anonymous · Answer

Alright, thank you. A quick question on a different question: 30x = 18x + 36 you would -18x get 12x = 36 then x = 3 right?

johnweldon1993 · Answer

Correct again!

anonymous · Answer

Alrighty, thank you sooo much (:

johnweldon1993 · Answer

No problem!