With one cup you can make 3 batches.
With 7 cups you can make 7*3=21 batches.
38: it's a right triangle
39:
area:


circumference:

3/4 x -18 = 1/4 x -4
subtract 1/4 x from each side
3/4 x -1/4 x -18 = 1/4 x- 1/4 x -4
2/4 x - 18 = -4
add 18 to each side
1/2 x -18 + 18 = -4 + 18
1/2 x =14
multiply by 2 on each side
2* 1/2 x = 14 * 2
x =28
P = s + (s + 5) + (s + 5) This represents the two sides that are 5 inches longer than the base (s + 5) and the base (s).
Simplifying.
100 = 3s + 10
subtract 10 from both sides
90 = 3s
divide both sides by 3
30 = s
base = 30
sides = 35
CHECK 30 + 35 + 35 = 100