Answer:
The slope is -4.5
The slope means that Elijah's phone battery will decrease by 4.5 percent each hour.
Step-by-step explanation:
In the equation y = mx + b, m is the slope.
The coefficient in the equation B = 27 – 4.5t is -4.5. This means that -4.5 is the slope of the equation.
In the context of this problem, the slope will represent the percent that Elijah's phone battery will decrease per hour.
So, the slope means that Elijah's phone battery will decrease by 4.5 percent each hour.
I don't think they are equivalent. try it yourself
Answer: 
Step-by-step explanation:
Given
Position of the particle moving along the coordinate axis is given by

Speed of the particle is given by

Acceleration of the particle is

velocity can be negative, but speed cannot
