91Ó°ÊÓ

Use two equations in two variables to solve each application. With the wind, a plane can fly 3,000 miles in 5 hours. Against the same wind, the trip takes 6 hours. Find the airspeed of the plane (the speed in still air).

Solve each system by graphing. Give each answer as a general ordered pair. SEE EXAMPLE 4. (OBJECTIVE 4) $$\left\\{\begin{array}{c} x=y \\ y-x=0 \end{array}\right.$$

Use elimination to solve each system. $$\left\\{\begin{array}{l}\frac{1}{2} x-\frac{1}{4} y=1 \\\\\frac{1}{3} x+y=3\end{array}\right.$$

Use substitution to solve each system. $$\left\\{\begin{array}{l}x=\frac{1}{2} y+\frac{5}{4} \\\4 x-2 y=5\end{array}\right.$$

Use two equations in two variables to solve each application. An airplane can fly downwind a distance of 600 miles in 2 hours. However, the return trip against the same wind takes 3 hours. Find the speed of the wind.

Use elimination to solve each system. $$\left\\{\begin{array}{l}\frac{3}{5} x+y=1 \\\\\frac{4}{5} x-y=-1\end{array}\right.$$

Use substitution to solve each system. $$\left\\{\begin{array}{l}3 a+6 b=-15 \\\a=-2 b-5\end{array}\right.$$

Graph the solution set of each system of inequalities, when possible. SEE EXAMPLE 7. (OBJECTIVE 4) $$\left\\{\begin{array}{l} x>2 \\ y \leq 3 \end{array}\right.$$

Determine whether the pair is a solution of the system. $$(3,2),\left\\{\begin{array}{l} x+y=5 \\ x-y=1 \end{array}\right.$$

Graph the solution set of each system of inequalities, when possible. SEE EXAMPLE 7. (OBJECTIVE 4) $$\left\\{\begin{array}{l} x \geq-1 \\ y>-2 \end{array}\right.$$