Answer:
The answer is B.
Explanation:
The question ask us to find an equation for the cost of a fill-up and a car wash. Firstly, we have to form 2 coordinates from the table and find the gradient :
Let Tank Size be x and Total Cost be y,
Any 2 coordinates,
Let (11,21.45) be (x1,y1) & (15,28.25) be (x2,y2),
m = (28.25-21.45)/(15-11)
= 6.8/4
= 1.7
You can form equation using slope-form, y = mx+b, then substitute m value and any coordinates into the equation :
Let m= 1.7 & (17,31.65),
y = mx + b
31.65 = 1.7(17) + b
31.65 - 1.7(17) = b
b = 2.75
y = 1.7x + 2.75