An airport has two long-term parking lots. The cost to park, y, in each lot for x days is shown in the tables. A system of linear equations can be used to determine on which day the cost to park is the same for both lots. One of the equations in the
system is y=6x. What is the other equation in the system?
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y = 4x + 12

Step-by-step explanation:

Hey there,

For Lot A I found the slope to be 4/1. You can do this by picking two points and finding the change in y over the change in x, or you can just look at the graph and realize that to get from one y variable to the other you're adding 4 and to get from one x variable to the other you're adding one. That means it's equal to 4/1 which is the same thing as 4. We know that at 1 the cost is $16. The y-intercept has to be equal to 12, meaning that they started off with $12 and are gaining $4 every day.

I hope this helps :)

c. y = 1/4 x + 5

step-by-step explanation:

first, put the equation of the line on the graph into slope-intercept form

(y = mx + b):   y = -4x + 8

second, a perpendicular line has to have "an opposite/reciprocal slope" to the original slope. so, find the "m" value in your original equation (it's -4, right? )

original slope: m = -4   perpendicular slope: change the sign to its opposite and find the reciprocal ("flip" the number)

new slope is now positive (b/c the original slope was negative 4), and it's 1/4 (not the original slope of 4 or 4/1)