Aschool will give its baseball teams up to $840 to buy new helmets. each helmet costs $20. the number of helmets, c, they can purchase is represented by the inequality 20c < 840. what's the maximum number of helmets the teams can buy?
a.28
b.32
c.41
d.44
e.84

26

step-by-step explanation:

answer: 204

step-by-step explanation:

we are told that the revenue is

x⋅(4080−10x)=−10x^2+4080x

this is a quadratic function, so to maximize it we should find the x-value of its vertex. recall that the x-value of the vertex of the parabola ax^2+bx+c is given by the formula −b/2a.

so in this case, we have a=−10 and b=4080, so the x-value of the vertex is

−b/2a= −(4080)/2(−10)=204