PLease help me with this math qestion

n+3 = 15 ; n = 12

3n -6 = 12;  n=6

Step-by-step explanation:

more than means it comes after

a number

n

3 more than

n+3

is 15

n+3 = 15

Subtract 3 from each side

n+3-3 = 15-3

n = 12

Subtract from comes after

three times a number

3n  

six subtracted from

3n -6

is 12 means equal to

3n -6 = 12

To solve add 6 to each side

3n -6+6 =12+6

3n = 18

Divide by 3

3n/3 =18/3

n =6

- "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."

answer: translate the circles so they share a common center point and dilate circle y by a scale factor of 3.