CPM Homework Help : CCA2 Problem 4-83

Solve the system of equations below. What sub-problems 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.

$−2(x+2y)=−2(4)$

$2x−y=−7$

Hint:

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

Answer:

$x=−2,y=3,z=−5$