The value of the first number, x, is eual to 2.
The value of the second number, y, is equal to -1.
The value of the third number, z, is equal to 8.
x + y + z = 9
y = x - 3
z = 2x + 4
Because we have values for y and z, we can find the exact value of x, which we can use to find the exact values for the other variables.
x + x - 3 + 2x + 4 = 9
Combine like terms.
4x + 1 = 9
Subtract 1 from both sides.
4x = 8
Divide both sides by 4.
x = 2
Now that we have a value for x, we can plug this value in to each other x value to solve for y and z.
y = 2 - 3
y = -1
z = 2(2) + 4
z = 8