Andre and Elena knew that after 28 days they would have 2²⁸ coins, but they wanted to find out how many coins that actually is. Andre wrote: 2 28 = 56. Elena said, “No, exponents mean repeated multiplication. It should be 28 28, which works out to be 784.”

c

step-by-step explanation:

at least i think its

- "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."