A company manufactures two types of athletic shoes, jogging shoes and cross trainers. The total revenue from x units of jogging shoes and y units of cross trainers is given by the following equation, where x and y are in thousands of units. R(x, y) = −6x2 − 8y2 − 4xy + 48x + 104y
Find the values of x and y to maximize the total revenue.

step-by-step explanation:

- "runner b is moving at a slower rate."

- "the graphs shown are graphs of distance(km) against time(min).

the slopes of this graphs are are given by:

slope = (change in y)/(change in x)

= (change in distance)/(change in time)

this is the formula for finding the speed. so, the slope of these graphs represent the speed of the runner.

taking each division in the graph to represent 1 on both axis:

runner a ⇒ speed = (2-0)/(1-0)

= 2/1

= 2 km/min

runner b ⇒ speed = (3-0)/(3-0)

= 3/3

= 1 km/min

this shows that   runner b is moving at a slower rate."