Answer:
The equation of the cost is C = 50h + 15
Step-by-step explanation:
The form of the linear equation is y = m x + b, where
- m is the slope of the line ⇒ rate of change
- b is the y-intercept ⇒ constant value
∵ A plumber charges 15 per service call
→ That means there is a fixed amount of 15
∵ b is the constant amount
∴ b = 15
∵ It charges 50 per hour
→ That means, the rate of change is 50
∵ m is the rate of change
∴ m = 50
∵ C is the cost for h hours
→ Replace y by C and x by h in the form of the linear equation above
∴ C = m h + b
→ Substitute the values of m and b in the equation
∵ C = 50h + 15
∴ The equation of the cost is C = 50h + 15
