You have taken over an abandoned drilling project. After drilling for 2 hours, the depth is 110 feet. After 5 hours, the depth has increased to 114.5 feet.

Question

Write an equation in from y=mx+b to describe the relationship between x, the hours of drilling, and y, the depth of the well

Answer 1

depth , d , = constant * time, t , + constant , b

d = m t + b
110.0 = 2 m + b
114.5 = 5 m + b
------------------------- subtract
- 4.5 = -3 m
so
m = 4.5 / 3
m = 1.5
so
d = 1.5 t + b
110.0 = 1.5*2 + b = 3 + b
b = 107.00
which is the depth at t = 0
d = 1.5 t + 107

Answer 2

(x, y).
(2, 110)
(5, 114.5).

m = (114.5-110)/(5-2) = 1.5.

Y = mx + b.
110 = 1.5*2 + b,
b = 107.

y = 1.5x + 107.