CPM Homework Help : A2C Problem 5-79

Solve the system of equations below. What subproblems did you need to solve?

$x + 2y = 4$
$2x − y = −7$
$x + y + z = −4$

Step 1:

Use the first two equations to solve for $x$ and $y$ using the Elimination Method.

$−2\left(x + 2y\right) = −2\left(4\right)$

$2x − y = −7$

Hint:

Now that you know $x$ and $y$ , how can you find $z$ ?

Answer:

$x = −2$ , $y = 3$ , $z = −5$