Lesson: Applications on Systems of Linear Equations in Three Variables Mathematics • 9th Grade

In this lesson, we will learn how to solve real-world problems using a system of linear equations in three variables.

Lesson Plan

Students will be able to

translate real-world problems into a system of linear equations and solve the system using substitution or elimination,
translate real-world problems into a system of linear equations and show that the system has no solutions,
translate real-world problems into a system of linear equations and show that the system has infinite solutions.

Lesson Playlist

02:41

Lesson Worksheet

Q1:

If the measure of one angle of a triangle is half the measure of the second angle and less than the measure of the third one by , then what are the measures of the three angles?

Q2:

Jackson, Daniel, and Jennifer each had 1 pound to spend in the candy shop. Jackson bought a packet of Stars and a bar of Coolies and got 13 pence in change. Daniel bought a packet of Stars and a Munch bar and got 17 pence in change. Jennifer bought a bar of Coolies and a Munch bar and got 40 pence in change. Their friend Hannah wanted to buy three packets of Stars, four bars of Coolies, and five Munch bars for her family. How much would it cost her?

Q3:

Sophia bought 3 plastic cars and 2 plastic boats for . Charlotte spent 4p less on 1 car, 1 boat, and 2 bikes. David got 2 boats and a bike for . How much does one plastic bike cost?