Just take 78 and divide by 3, he gets 26 mpg with his car.
9x + 3 = 7x +19
2x + 3 = 19
2x = 16
x = 8
So, x (8) is the number of chairs in each row with these setups.
Plug 8 into one of the equations and you will find how many chairs total there are.
9(8) + 3 = 75
There are 75 chairs total
I hope this helps. Keep in mind the 1/3 is slope and the 3 is y-intercept.
X=-1
Trust me yurrrrrrrrrr
When you are checking your answers, your formula should read out as 9(2.222) - 8 = 12, which is simply filing in the x value that you calculated (it comes out to 11.998 which is correct). You wrote it out as 9(2.22) - 8 = -6, which is why your checking process was incorrect
