Solving systems by substitution can be a challenging topic in algebra I. Here is a lesson plan that builds on students' understanding of intercepts to begin the process of substitution, and all work is reinforced graphically to...

How many large and small watermelons did he sell? Just use the given information to write and solve a system of equations! The two videos accompanying the lesson explain the substitution method and then introduce problem solving. The...

If at first you cannot graph, substitute. The lesson introduces the substitution method as a way to solve linear systems if the point of intersection is hard to determine from a graph. The 28th installment of a 33-part series finishes...

Put all that algebra learning to use! Using algebraic strategies, learners solve three-variable systems. They then use the three-variable systems to write a quadratic equation given three points on the parabola.

Discover how algebra tiles help evaluate expressions. Scholars learn to use algebra tiles to substitute values in for variables and evaluate expressions. The included worksheet contains a set of evaluation problems to assess individuals'...

Time for pupils to use their imagination! Learners examine the relationship between a system with no real solution and its graph. They then verify their discoveries with algebra. 

In this third of a twelve-part series, the focus moves from using matrices to solving systems of equations with substitution and elimination, including more than two dimensions and variables in equations, and analyzing statistical data....

Explore nonlinear systems through graphs and algebra. High schoolers begin by examining the different types of quadratic functions and their possible intersections. They then use algebraic methods to solve systems containing various...

Round and round they go ... where they stop, only scholars will know. By writing systems of equations, classes determine the number of cars a roundabout can handle given specific constraints. Systems use up to six variables and become...

What does it mean to solve an equation? The resource revisits the concept of making a linear equation true. Classmates use algebraic methods to transform sides of equations to expressions with fewer terms. They use substitution to...

Here is a fun project. Sammy observes a chipmunk and a squirrel to see how many holes each needs in order to stash the same number of acorns.  Scholars could find the answer algebraically or create a table to analyze the...

The brother-sister pair Carlos and Clarita need your class's help in developing their new pet sitting business. Through a variety of scenarios and concerns presented to the siblings, the learners thoroughly explore systems of equations...

Substitution is still the method of choice to verify number sentences. The detailed lesson has young mathematicians determining conditions for when number sentences are true or false through substitution. They learn to express these...

Many things in life take the shape of a polynomial curve. Learners design a polynomial function to model a riverbed. Using different strategies, they find the flow rate through the river.

The rides at a theme park always have limits on weight or number of riders. This makes a natural example of the use of inequalities to solve real-world problems. Learners explore intuitive solutions using substitution to solve the...