We know that the equation is of the following form.
y=mx
To determine the equation we need to find m, which is the slope of the line. Let's recall the formula for the slope of a line that passes through the points (x_1,y_1) and (x_2,y_2).
m=y_2-y_1/x_2-x_1
We are already given some of the coordinates!
m=280-y_1/x_2-2
Let's try to complete this. We need to find y_1 and x_2, so that the line passes through the points (2, y_1) and ( x_2,280). Observing the given graph, we can see that the line passes through the points (2, 140) and ( 4,280).
We found that y_1= 140 and x_2= 4. Now, we can complete the substitution.
m=280-y_1/x_2-2 ⇕
m=280-140/4-2
Let's simplify this to calculate the slope
m=280-140/4-2=140/2= 70
We found that the slope m is equal to 70. Finally, we can write the equation of the given line.
y=70 x
In Part A we found an equation that represents the relationship between the number of heartbeats and time.
y= 70x
Also, we found that the slope of the line m is equal to 70. This means that the number of heartbeats increases by 70 each minute.
Therefore, we can write the following conclusion.
&The heart's resting rate is70 &beats per minute.
