The sum of three numbers is 56 . The second number is 2 times the third. The first number is 8 less than the third. What are the numbers?

Question

 I don't know how too do it

Answer 1

X + Y + Z = 56
Y = 2Z
X = Z – 8

Substitute the values from the second and third equation into the first equation:
Z – 8 + 2Z + Z = 56
Simplify
-8 + 4Z = 56
4Z = 64
Z = 16

So if Y = 2Z, Y = 2(16) = 32
And if X = Z – 8, X = 16-8 = 8

X = 8
Y = 32
Z = 16