Answer:
Cab B charged more
It charged $(30-x) more
Explanation:
Here, we want to know which of two cabs charged more for a ride from the airport to the mall.
To know the cab that charged more, we shall be substituting any same value of x in both of the fees
Let’s say x is 10
Thus 5x + 20 becomes 5(10) + 20 = 50 + 20 = 70
while 4x + 50 becomes 4(10) + 50 = 40 + 50 = 90
Clearly we can see that 4x + 50 is greater then 5x + 20, so we can conclude that 4x + 50 is a greater fee
Now since we know the one that’s higher, we can now know the value by which it is higher
That would be (4x + 50)-(5x + 20)
= 4x + 50 -5x -20
= 4x-5x + 50-20
= -x + 30 or simply 30-x