Answer:
let x equal the service charge.
let y equal the per hour charge.
for the job that cost 450, the equation is 450 = x + 6y
for the job that cost 330, the equation is 330 = x + 4y
these two equations needs to be solved simultaneously.
subtract the second equation from the firs to get 120 = 2y
solve for y to get y = 60.
in the first equation, replace y with 60 to get 450 = x + 6*60.
simplify to get 450 = x + 360.
subtract 360 from both sides of the equation to get 90 = x.
it appears that the service charge is equal to 90 and the per hour charge is equal to 60.
for the job that cost 450, the equation becomes 450 = 90 + 6*60 = 90 + 360 = 450.
for the job that cost 330, the equation becomes 330 = 90 + 4*60 = 90 + 240 = 330.
the numbers check out.
the service charge is 90.
the per hour charge is 60.
i believe your solution is that the electrician charges a flat fee of 90 plus an hourly fee of 60 for a service call.
Step-by-step explanation:
