91Ó°ÊÓ

Solve the system by either the substitution or the elimination method. $$ \left\\{\begin{array}{l} {-4 x=-3 y-13} \\ {-6 x+8 y=-16} \end{array}\right. $$

Farming. In a pen of goats and chickens, there are 40 heads and 130 feet. How many goats and chickens are in the pen?

Solve each system by substitution. If a system has no solution or infinitely many solutions, so state. $$ \left\\{\begin{array}{l} {5 y+2=-4 x} \\ {x+2 y=-2} \end{array}\right. $$

Solve each system of equations by graphing. $$ \left\\{\begin{array}{l} {y=2 x-4} \\ {y=-5 x+3} \end{array}\right. $$

Simplify each expression. $$ 8\left(\frac{3}{4} t\right) $$

Solve each system of equations by graphing. $$ \left\\{\begin{array}{l} {-x+3 y=-11} \\ {3 x-y=17} \end{array}\right. $$

Solve the system by either the substitution or the elimination method. $$ \left\\{\begin{array}{l} {9 x-10 y=0} \\ {\frac{9 x-3 y}{63}=1} \end{array}\right. $$

Solve each system by substitution. If a system has no solution or infinitely many solutions, so state. $$ \left\\{\begin{array}{l} {2 x+5 y=-2} \\ {y=-\frac{x}{2}} \end{array}\right. $$

Solve each system of equations by graphing. $$ \left\\{\begin{array}{l} {2 x-3 y=-18} \\ {3 x+2 y=-1} \end{array}\right. $$

Solve each system by substitution. If a system has no solution or infinitely many solutions, so state. $$ \left\\{\begin{array}{l} {y=-\frac{x}{2}} \\ {2 x-3 y=-7} \end{array}\right. $$