we know that
A direct variation is a mathematical relationship between two variables that can be expressed by an equation
y=kx
the rate of change is equal to the slope of a line
k=m
step 1
Find the slope of the graph
let
A(0,0)
B(10,50)
m=(y2-y1)/(x2-x1)------> m=(50-0)/(10-0)------> m=50/10-----> m=5
therefore
the equation is
y=5x
the answer is
the rate of change is 5