A computer can sort x objects in t seconds, as modeled by the function below:

t=0.005x^2+0.002x

How many objects are required to keep the computer busy for exactly 9 seconds?

Round to the nearest whole object.

Question

A computer can sort x objects in t seconds, as modeled by the function below:

t=0.005x^2+0.002x

How many objects are required to keep the computer busy for exactly 9 seconds?

Round to the nearest whole object.

anonymous · Answer

I believe I know the way to solve this.  Lemme know when you're ready to work on this together.

anonymous · Answer

ready

anonymous · Answer

Awesome. So you know it's a quadratic equation, right?

anonymous · Answer

ya

anonymous · Answer

Mmk.  And you're familiar with the quadratic equation?

anonymous · Answer

mhmm

anonymous · Answer

Alright. So we need it to be in the form of Ax^2 + Bx + C = 0.
Unfortunately, it's currently in the form of 9 = Ax^2 + Bx

So what do we do to correct this?

anonymous · Answer

move the 9 to the other side

0=0.005x^2+0.002x-9

anonymous · Answer

Perfect.  And then just plug it into the quadratic equation.  Tell me what you get after doing it.

anonymous · Answer

46.47 & -46.47

anonymous · Answer

Ah, sorry for the late reply.  I actually got a slightly different answer:
42.2 and -42.6

Just recheck the equation (I could be the wrong one).  And pick the positive answer, since you can't give a negative amount of equations to the computer.