91Ó°ÊÓ

Graph each ordered pair on a coordinate grid.

$(−3,3)$

Determine whether each equation is a linear equation. Write yes or no. If yes, write the equation in standard form.

$y=−4x+3$

The equation to convert Celsius temperature C to Kelvin K is shown.

1. State the independent and dependent variables. Explain.
2. Determine the C- and K-intercepts mean in this situation.

Write the ordered pair for point D.

Solve each equation by graphing.

$−5x+35=0$

Suppose yvaries directly as x. Write a direct variation equation that relates x and y. Then solve.

If$y=6$ when $x=9$, find x when $y=12$.

Solve each equation for y.

$3x+4y=10$

A hot air balloon was at a height of 60 feet above the ground when it began to ascend. The balloon climbed at a rate of 15 feet per minute.

a. Make a table that shows the height of the hot air balloon after climbing for 1, 2, 3, and 4 minutes.

b. Let t represent the time in minutes since the balloon began climbing. Write an algebraic equation for a sequence that can be used to find the height h, of the balloon after tminutes.

c. Use your equation from part b to find the height, in feet, of the hot air balloon after climbing for 8 minutes.

The distance d in kilometers that sound waves travel through water is given by$d=1.6t$, where t is the time in seconds.

1. Make a table of values and graph the equation.
2. Use the graph to estimate how far sound can travel through water in 7 seconds.

The number of pints of blood in a human body varies directly with the person’s weight. A person who weighs 120 pounds has about 8.4 pints of blood in his or her body.

a. Write and graph an equation relating weight and amount of blood in a person’s body.

b. Predict the weight of a person whose body holds 12 pints of blood.