I think only the first two
Answer:
where
is the amount of banners sold.
Step-by-step explanation:
We know the team has already spent $40, and they earn #3.5 per banner.
Hence, with
representing the amount of banners sold, the equation is 
If C is between A and B, then, we can write the equation

Substitute the value of AB and the expressions for AC and CB in terms of x.

We can now solve for x.


Dividing by 5.








Answer:
18 units
Step-by-step explanation:
So let's list out the sides.
for the first square let's just call them x
for the second square then they would be x+5 and x-3
So let's write out their areas we will cal the area of the first one z
x*x = z
(x+5)*(x-3) = z+21
since z = x^2 we can set up the second equation as a quadratic.
(x+5)*(x-3) = x^2 + 21
x^2 - 3x + 5x - 15 = x^2 + 21
But look, the x^2s cancel out
2x - 15 = 21
2x = 36
x = 18
Test it out and see if it fits the description, And if you don't understand anything just let me know so I can explain more.