Which expression represents the volume of the square pyramid shown? a) 7x + 8 b) 3x3 + 24x2 c) 9x3 + 72x2 d) 9x2 + x + 15

  B)3x^3 + 24x^2

Step-by-step explanation:

The volume of a pyramid is 1/3 the product of the base area and the height. The base is square, so its area is the square of the side dimension.

  V = (1/3)(3x)^2(x+8) = 3x^2(x +8)

  V = 3x^3 +24x . . . . . matches B

10

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."