What is a rate in math ?

the question
> what was the heart rate for the students with the lowest heart rate?

78,80,82,83,84,85,86,87,88,90

i did it myself and i got 4.2 (b) hope its right

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

2/3

step-by-step explanation: