Hi there. New member here, I hope someone can help with this problem.

The president of a company producing water pumps has gathered data that suggests that the average cost in dollars of producing x pumps will be
C(x)=x^2-21x+100.Determine the number of pumps that the company needs to produce in order to have an average cost to 28$per pump. Can't factor It what to do? 2. ## Re: Please help solve this completly Originally Posted by MathQuestion82 Hi there. New member here, I hope someone can help with this problem. The president of a company producing water pumps has gathered data that suggests that the average cost in dollars of producing x pumps will be C(x)=x^2-21x+100.Determine the number of pumps that the company needs to produce in order to have an average cost to 28$ per pump.

Can't factor It what to do?
The cost to manufacture x pumps is

$C(x)=x^2-21x+100$

If the average cost is \$28 per pump then the total cost for x pumps is$28x$so$C(x)=x^2-21x+100=28x$Just rearrange this and apply the quadratic formula to solve for the roots of this equation. I'm actually seeing two valid answers though one is more realistic than the other. 3. ## Re: Please help solve this completly Originally Posted by romsek The cost to manufacture x pumps is$C(x)=x^2-21x+100$If the average cost is \$28 per pump then the total cost for x pumps is $28x$

so

$C(x)=x^2-21x+100=28x$

Just rearrange this and apply the quadratic formula to solve for the roots of this equation.

I'm actually seeing two valid answers though one is more realistic than the other.
So this is not correct?

x^2 - 21x + 100 = 28
x^2 - 21x + 100 - 28 = 0
x^2 - 21x + 72 = 0

x= 21/2 +- V(21/2)^2 -72

V represents square root.

x= 10.5+-V38.25
x=10.5+-6.1844658438

x1=4.315341562
x2=16.68465844

similar problem someone did it like me
SOLUTION: Hi, please help me answer this question: The president of a company producing water pumps has gathered data suggesting that the average cost in dollars producing x units per hou

Of course doesn't mean it's correct. But are you 100%?

Thanks for the help