Lesson 3: Practice Problems

Problem 1

Here is an equation that represents a function: $72 x + 12 y = 60$ .

Select all the different equations that describe the same function:

$120 y + 720 x = 600$
$y = 5 - 6 x$
$2 y + 12 x = 10$
$y = 5 + 6 x$
$x = \frac{5}{6} - \frac{y}{6}$
$7 x + 2 y = 6$
$x = \frac{5}{6} + \frac{y}{6}$

Problem 2 From Unit 5 Lesson 14

Graph a system of linear equations with no solutions.
Write an equation for each line you graph.

Problem 3

Brown rice costs $2 per pound, and beans cost $1.60 per pound. Lin has $10 to spend on these items to make a large meal of beans and rice for a potluck dinner. Let $b$ be the number of pounds of beans Lin buys and $r$ be the number of pounds of rice she buys when she spends all her money on this meal.

Write an equation relating the two variables.
Rearrange the equation so $b$ is the independent variable.
Rearrange the equation so $r$ is the independent variable.

Problem 4 From Unit 4 Lesson 14

Solve each equation and check your answer.

$2 x + 4 (3 - 2 x) = \frac{3 (2 x + 2)}{6} + 4$
$4 z + 5 = - 3 z - 8$
$\frac{1}{2} - \frac{1}{8} q = \frac{q - 1}{4}$