Answer:
$110
Step-by-step explanation:
Let the fixed amount charged be f and the amount charged to clean a room be r.
To clean six rooms , the company would charge the following, the fixed amount for the call plus the amount charged per room multiplied by 6 which of course is 6r.
Writing this in equation form,
f + 6r = 250
In likewise manner, same applies for 8 rooms.
this gives f + 8r = 320
We now have 2 equations that we will need to solve simultaneously
f + 6r = 250........(i)
f + 8r = 320........(ii)
We subtract equation ii from I to yield
2r = 70, hence r = 70/2 = 35.
We now substitute this in equation 1
f + 6(35) = 250
f + 210 = 250
f = 250 - 210 = 40
Hence, we now know that the amount charged per call is $40 while the amount charged to clean a room is $35.
We now calculate the amount charged by the company to clean 2 rooms.
This is mathematically = f + 2r
40 + 2(35) = $110.