Answer:
Step-by-step explanation:
Step 1: The general equation of straight line is
y = mx + c
c = initial value
m = rate of change
Step 2: Initial value c = 20
Step 3: Rate of change
m = [tex]\frac{y2 - y1}{x2 - x1}[/tex]
Step 4: From the graph, pick two points
x1 = 0, y1 = 20
x2 = 4, y2 = 2
Step 5: By substitution, rate of change m = [tex]\frac{21-20}{4-0}[/tex]
m = [tex]\frac{1}{4}[/tex]
Step 6: Equation of the graph
y = mx + c
y = [tex]\frac{1}{4}x[/tex] + 20
