Linear Inequalities Review
Date:
Tips:
* Substitute to see if points are solutions of inequalities
* Restrictions: Real, Whole or Integers
* Inequalities: For word problems, include: 𝑥 ≥ 0, 𝑦 ≥ 0
* Optimization:
- Make an objective function using the money information for this equation.
- Substitute the intersection points of the lines
Ex. 1 How would you graph the solution set for the linear inequality 4y – 2x < 20?
a.
b.
c.
d.
Draw a dashed boundary line y =
x + 10, then shade above the line.
Draw a dashed boundary line y =
x + 10, then shade below the line.
Draw a solid boundary line y =
x + 10, then shade below the line.
Draw a solid boundary line y =
x + 10, then shade above the line.
Ex. 2 A pet store specializes in birds.
• It sells at least four times more male birds than female birds of the same species. The males’ colourful feathers
make them more popular.
• Over the past month, no more than 40 birds, in total, have been sold.
• Males were sold for $120, and females were sold for $75.
a. Define the variables.
b. Determinate the restrictions, if any on the variables.
c. Write a system of linear inequalities that represent this situation.
d. Graph the system of linear inequalities and shade in the solution set.
e. What combinations of sales of male and female birds would have maximized the pet store’s
revenue?
HW: p. 349: #1a, 3, 5a, 6, 7, 9, 10