Math calculus Question

Question

Solve the following applied problem using a system of equations. The sum of three numbers is 35. The second number is twice the first, and the third number is twice the second. What are the numbers?

Answer 1

1. x + y + z = 35; The sum of three numbers is 35.
2. y = 2x; The second number is twice the first
3. z = 2y = 4x; the third number is twice the second
4. substituting from 2 and 3 into 1: x + 2x + 4x = 35 => x = 5
5. From 4 into 2, y = 10
6. From 5 into 3, z = 20
7. So, (x,y,z) = (5, 10, 20)

Answer 2

n = the first number

2n = the second number (i.e. twice the first number)

2(2n) = the third number (i.e. twice the second number)

n + 2n + 2(2n) = 35

Can you solve for n and finish from here?