SWBAT connect solving systems of equations by graphing to solving systems by substitution and discuss when using an equation is more accurate.

Connect solving systems of equations to real life baseball helmets and reading tables to find the equations for solving by substitution.

10 minutes

Write the following on the board:

Find solution(s) that make the following equations true:

(2/3)x - 14 = 3(4x + 5)2y + 4 = x-2(5x - 4) = 8 - 10x2x^2 = -14

The goal of this bellringer is to review with students the algebraic process of solving equations and to make them think about solutions to equations. Some equations have only one solution, some infinite solutions, and others no solution. The lesson today is trying to guide students to solve systems of equations by using substitution and getting more algebraic when the given equations are in slope intercept form.

Allow students time to work within cooperative groups to answer each of these equations: The first equation has one solution, second has infinite solutions, third is all real numbers, and last equation is no solution. Move about the room providing feedback to move learning forward and listen to conversations to decide who you want to present to the whole group because their thinking is so valuable and algebraic. You want students who present to the class to discuss the structure of the equation and how it determined the number of possible solutions. Have student groups come to the board and explain how they arrived at their solution for a given equation.

30 minutes