91Ó°ÊÓ

Solve each system. $$ \left\\{\begin{array}{r} {5 y-7 z=14} \\ {2 x+y+4 z=10} \\ {2 x+6 y-3 z=30} \end{array}\right. $$

Graph the solutions of each system of linear inequalities. See Examples I through 3. $$ \left\\{\begin{array}{r} {-2 x>y} \\ {x+2 y<3} \end{array}\right. $$

Solve each system. $$ \left\\{\begin{aligned} x &+5 z=0 \\ 5 x+y &=0 \\ y-3 z &=0 \end{aligned}\right. $$

Karen Karlin bought some large frames for \(\$ 15\) each and some small frames for \(\$ 8\) each at a closeout sale. If she bought 22 frames for \(\$ 239,\) find how many of each type she bought.

Solve each system of linear equations using matrices. See Example 3 . $$ \left\\{\begin{array}{r} {2 y-z=-7} \\ {x+4 y+z=-4} \\ {5 x-y+2 z=13} \end{array}\right. $$

Solve each system. $$ \left\\{\begin{aligned} x-5 y &=0 \\ x &-z=0 \\ -x &+5 z=0 \end{aligned}\right. $$

Hilton University Drama Club sold 311 tickets for a play. Student tickets cost 50 cents each; nonstudent tickets cost S1.50. If total receipts were \(\$ 385.50,\) find how many tickets of each type were sold.

Graph the solutions of each system of linear inequalities. See Examples I through 3. $$ \left\\{\begin{array}{l} {x \geq-3} \\ {y \geq-2} \end{array}\right. $$

Solve each system by graphing. See Examples 2, through 4. $$ \left\\{\begin{array}{l} {3 x-y=4} \\ {6 x-2 y=4} \end{array}\right. $$

Solve each system. $$ \left\\{\begin{array}{ll} {6 x-5 z=} & {17} \\ {5 x-y+3 z=} & {-1} \\ {2 x+y} & {=-41} \end{array}\right. $$