Question

In the table below, x represents miles traveled and y represents the cost to travel by train.

Miles, x
Cost, y
2
8.50
5
15.25
8
22.00
12
31.00

Which linear equation represents the situation?

y = 2 x + 8.50
y = 2.25 x + 4.00
y = 6.50 x + 2.25
y = 12 x + 22.50

Answer 1

The second equation is correct.

y=2.25x + 4

Explanation:

We can systematically eliminate the others.

For equation 3 and 4, 6.5*2 and 12*x is already bigger than 8 of the first set of numbers.

For equation 1, 2*x+8.5 is also bigger than 8 from the first set.

Plugging in the values to equation 2, we always get the correct cost.