CPM Homework Help : A2C Problem 10-21

Solve this system for $y$ and $z$ :

$\left. \begin{array} { r } { \frac { z + y } { 2 } + \frac { z - y } { 4 } = 3 } \\ { \frac { 4 z - y } { 2 } + \frac { 5 z + 2 y } { 11 } = 3 } \end{array} \right.$

Hint:

Eliminate the denominator in both equations and simplify them before solving.

Step 1:

$\left(\frac{z +y}{2}+\frac{z - y}{4} = 3\right)4$

$\left(\frac{4z-y}{2} + \frac{5z+2y}{11} = 3\right)22$

Step 2:

$2z + 2y + z − y = 12$

$44z − 11y + 10z + 4y = 66$

Step 3:

$3z + y = 12$

$54z − 7y = 66$