### Home > INT3 > Chapter 12 > Lesson 12.1.4 > Problem12-62

12-62.

Solve the system of equations below.

$\left. \begin{array} { l } { x + y + z = 40 } \\ { y = x - 5 } \\ { x = 2z } \end{array} \right.$

Use substitution to solve.

If $x = 2z$, then $y = 2z − 5$.

Now that you have expressions for both $x$ and $y$ in terms of $z$, substitute them into the first equation and solve for $z$.
Then solve for $x$ and $y$.