For every 140 feet that kelly rides on her bicycle, the wheels turn 20 times. About how many times do the wheels turn in 5 miles? ( 1 mile = 5,280 feet)

Approximately 3771 times

Step-by-step explanation:

Let x be the number of times the wheels turn in 5 miles.

Given that, 1mile = 5,280ft

Thus, 5 miles=5 × 5,280ft=26400ft

From the question ,we can deduce the following ratios :

140 ft : 20 mins

26400ft : x

Cross multiply;

Divide through by 140.

i think the answer is b.

step-by-step explanation:

not 100% sure though.

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