Answer:
The speed is constant.
Step-by-step explanation:
The equation for a straight-line graph is
y = mx + b
where m and b are constants.
m is the slope of the line and b is the y-intercept.
If we change the variables, the equation becomes
d = mt + b
![m = (\Delta d)/(\Delta t) = = \frac{\text{ distance}}{\text{time}} = \text{speed}](https://img.qammunity.org/2019/formulas/chemistry/middle-school/i3eub14s26g4ae4j3cqfp04fhp7iinthot.png)
Since m is constant, so is the speed.