30 students could of been taking both courses and 60 with no course
Answer: Vertical line x = 1
<u>Step-by-step explanation:</u>
(1, 1) (1, 2) (1, 3) (1, 4)
Notice that the x-value for each coordinate is 1.
The line is a vertical line (up & down) through x = 1
Answer is x+9=11
6+x=9
x=3
15=x+12
x=3
7+x=10
x=3
x+9=11
x=2
So x+9=11 has a different x value than the rest of the equations. So it doesn't belong with the other three.
I would choose the answer D