This equation is in slope-intercept form; y = mx+b.
m is the slope and b is the y-intercept, so to find the slope you'd look at the coefficient of x.
In this equation, y = 3x+5, the coefficient of x is 3, so that means that the slope of this equation is 3.
Answer is:
3 is the slope
Complete question
A 29-meter ladder is sliding down a vertical wall so the distance between the top of the ladder and the ground is decreasing at 7 meters per minute. At a certain instant, the bottom of the ladder is 21 meters from the wall.
What is the rate of change of the distance between the bottom of the ladder and the wall at that instant(in meters per minute)
Answer:

Step-by-step explanation:
From the question we are told that
Slant height 
Change in Vertical height 
Horizontal length 
Generally in finding the distance form the top to the bottom of the wall it is mathematically given by




Generally solving for the differential equation is mathematically represented as







Opposite side = sqrt (3^2 - 2^2 ) = sqrt5
sin theta = -sqrt 5 / 3 as the sine is negative in the 3rd quadrant
csc theta = - 3 / sqrt5