$4
You can get this by setting up 2 equations. One for you and one for your friend. Each should have a cost equation. Let x = adult and y = student.
You: 7x + 16y = 120
Friend: 13x + 9 = 140
Solve using any method.
Answer:
1117 km
Step-by-step explanation:
Because the two cities are approximately on the same North-South line, they are on the same longitude. The difference in their latitudes is 39° - 29° = 10°. We are subtracting because they are both in the northern hemisphere. The distance between them is

4 = (r-2) t
8 = (r+2) t
4 = (r-2) * [8/(r+2)]
4 = (8r-16)/ (r+2) . . .multiply by 2
4r + 8 = 8r - 16
4r = 24
r = 6
hope this helps
Both sides equal each other. Do you want to know how?
√(4 + 16 + 16√3 + 12) = 4√(2 + √3)
Surd Rule: Numbers with the same surd can be added together. Therefore, all whole integers can be added together.
√(4 + 16 + 16√3 + 12)
√((4 + 16 + 12 )+ 16√3 ) =
√(32 + 16√3)
Simplify by Factorising the common factor - 16
√(32 + 16√3) ÷ 16
√(16 (2 + √3))
Square root 16. This is because it is a not a surd because it is not in it's simplest form.
√16 = 4
√4 (2 + √3)