The problem states two given conditions:
One is that after 1 hour, Estelle has two bags of leaves and after three hours she has 6 bags of leaves.
The equation of a line is y=mx + b where m is the slope and b is the y-intercept of the line graph
Plotting the two points to get the m and b:
(1, 2) and (3, 6)
2=m*1 + b ; b= 2-m eqn 1
6=m*3 +b eqn 2
Solving for m and b can be done using systems of linear equations or by substituting equation 1 to equation 2.
m=2 and b=0
So the equation of the line in the graph is y=2x