Answer:
A. and C.
Step-by-step explanation:
We don't know the area of the roof or the number of people in the group so they would both be represented by variables in an equation.
Answer:

Step-by-step explanation:
1kx + 13kx = 6
14kx = 6
÷(14k) ÷(14k)
x = 6/(14k)
x = 3/(7k)
Here's my work. Hope it helps.
Step-by-step explanation:
3d + 4.5g <= 18.
3 possible combinations are:
0 DVD and 4 Video games,
1 DVD and 3 Video games,
2 DVDs and 2 Video games.