Question

Jennifer has a taco stand.she found that her daily costs can be modeled by C(x)=x^2-40x+610. if she wants to keep her daily cost at 300 dollars, how many units of tacos does she need to sell

Answer 1

Plug in 300 for C(x), to get:
300=$x^{2} -40x=610$
Then subtract to get: 0=$0= x^{2} -40x+310$
Then use the quadratic formula and plug everything in. Use a calculator to simplify.

You'll get two answers: 29.486 and -0.513.
Since you can't sell "negative" tacos, use the positive solution
Around 29-30 tacos.