T = 30
A = 4c
A + c = T
Anna Claire has 6 pencils. Times 4 makes Ally's pencil count. 4 * 6 = 24
24 + 6 = 30. So, you answer is: Ally has 24 pencils.
Hypotenuse or C (x) can be found with the equation

After solving you get about 6.32
6.32 about the same as
y = 4 + 3x
4 being the entrance cost and 3x being the 3 dollars per pound