91Ó°ÊÓ

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

Solve the system by either the substitution or the elimination method. $$ \left\\{\begin{array}{c} {4(x-2 y)=36} \\ {3 x-6 y=27} \end{array}\right. $$

Explain why a table is helpful in solving uniform motion and mixture problems.

Solve each system by substitution. If a system has no solution or infinitely many solutions, so state. $$ \left\\{\begin{array}{l} {x+2 y=-6} \\ {x=y} \end{array}\right. $$

Solve the system by either the substitution or the elimination method. $$ \left\\{\begin{aligned} 2(x+2 y) &=15 \\ 3 x=8 &-6 y \end{aligned}\right. $$

A man paid \(\$ 89\) for two shirts and four pairs of socks. If we let \(x=\) the cost of a shirt, in dollars, and \(y=\) the cost of a pair of socks, in dollars, an equation modeling the purchase is \(2 x+4 y=89 .\) Explain why there is not enough information to determine the cost of a shirt or the cost of a pair of socks.

Solve each system by substitution. If a system has no solution or infinitely many solutions, so state. $$ \left\\{\begin{array}{l} {y=2 x-9} \\ {x+3 y=8} \end{array}\right. $$

Solve each system of equations by graphing. $$ \left\\{\begin{array}{l} {x+y=1} \\ {y=x+5} \end{array}\right. $$

Solve each system of equations by graphing. $$ \left\\{\begin{array}{l} {x=3} \\ {3 y=6-2 x} \end{array}\right. $$

Solve the system by either the substitution or the elimination method. $$ \left\\{\begin{array}{l} {x=y} \\ {0.1 x+0.2 y=1.0} \end{array}\right. $$