Answer:
First number: 16
Second number: 50
Third number: 25
Step-by-step explanation:
Let's call the first number x, the second number y, and the third number z.
The sum of the three numbers is 91, so
x + y + z = 91
The third number is 9 more than the first, so
z = 9 + x
The second number is 2 times the third
y = 2z
Therefore, we have the following system of equations
x + y + z = 91
z = 9 + x
y = 2z
If we solve the second equation for x, we get
z = 9 + x
z - 9 = 9 + x - 9
z - 9 = x
Now, we can replace x = z - 9 and y = 2z on the first equation and solve for z
x + y + z = 91
(z - 9) + (2z) + z = 91
z - 9 + 2z + z = 91
4z - 9 = 91
4z - 9 + 9 = 91 + 9
4z = 100
4z/4 = 100/4
z = 25
With the value of z, we can calculate the values of x and y
x = z - 9
x = 25 - 9
x = 16
y = 2z
y = 2(25)
y = 50
Therefore, the answers are
First number: 16
Second number: 50
Third number: 25