Need help ASAP will mark brainliest

  5x -7y = 21

Step-by-step explanation:

A sketch can convince you that BC is a transversal perpendicular to parallel lines AB and CD. The question asks for an equation for CD, so we just need to write the equation of a line through D that is parallel to AB.

One way to do this is to equate the slopes of the parallel lines:

  ∆y/∆x for AB = ∆y/∆x for CD

  (y2 -y1)/(x2 -x1) = (y -2)/(x -7) . . . . . . where (x1, y1) = A; (x2, y2) = B; (7, 2) = D

  (4 -(-1))/(1 -(-6)) = (y -2)/(x -7)

  5(x -7) = 7(y -2) . . . . . . . . . . . . . cross multiply

  5x -7y = 21 . . . . . . . . . . . . . . . . add 35 -7y, simplify

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Note that the graph shows the line CD is named "b", and its equation is shown at upper left. Multiplying that equation by -1 gives the one shown here.

1e+27

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."