Question

example 2

1. exercise carlos is jogging at a constant speed. he starts a timer when he is 12 feet from his starting position. after 3 seconds, carlos is 21 feet from his starting position. write a linear equation to represent the distance d of carlos from his starting position t seconds after starting the timer.

Explanation:

Step1: Identify known values

Initial distance: $d_0=12$ ft at $t=0$; distance $d_1=21$ ft at $t=3$ s

Step2: Calculate speed (slope)

Speed $m=\frac{21-12}{3-0}=\frac{9}{3}=3$ ft/s

Step3: Write linear equation

Use $d=mt+d_0$, substitute $m=3, d_0=12$

Answer:

$d=3t+12$