TODAY IN ALGEBRA…

Learning Goal: 7.2 You will solve systems of linear equations by Substitution

Independent Practice

7.2 SOLVING LINEAR SYSTEMS BY SUBSTITUTIONREMEMBER… A linear system is two or more linear equations

And the solution is where the graphs intersect

I can also find this solution WITHOUT GRAPHING, Here’s how…..

7.2 SOLVING LINEAR SYSTEMS BY SUBSTITUTION

STEPS FOR SOLVING A LINEAR SYSTEM BY SUBSTITUTION:

STEP 1: Solve for 1 variable for one of the two equations (it doesn’t matter which equation you start with and which variable you choose to solve for).

STEP 2: Substitute one equation into the other and solve for the given variable.

STEP 3: Substitute the solution from STEP 2 into the equation you solved for from STEP 1 and solve for the given variable.

THIS IS MUCH EASIER WITH AN EXAMPLE!

7.2 SOLVING LINEAR SYSTEMS BY SUBSTITUTIONEXAMPLE 1: Solve the linear system

STEP 1: Solve for one variable: is already solved for y!

STEP 2: Substitute into and solve for x:

3 𝑥+2

STEP 3: Substitute into

Write your solution as a point!

STEP 2 continued… STEP 3: Substitute into SOLUTION:

7.2 SOLVING LINEAR SYSTEMS BY SUBSTITUTIONEXAMPLE 2: Solve the linear system

STEP 1: Solve for one variable: I will solve for x in : STEP 2: Substitute into and solve for x:

−6+2 𝑦

STEP 2 continued… STEP 3: Substitute into SOLUTION:

7.2 SOLVING LINEAR SYSTEMS BY SUBSTITUTIONEXAMPLE 3: Solve the linear system

STEP 1: Solve for one variable: I will solve for y in : STEP 2: Substitute into and solve for x:

−7−3 𝑥

7.2 SOLVING LINEAR SYSTEMS BY SUBSTITUTIONPRACTICE 1: Solve the linear system

STEP 1: Solve for one variable: is already solved for y!

STEP 2: Substitute into and solve for x:

2 𝑥+5

STEP 3: Substitute into

Write your solution as a point!

STEP 2 continued… STEP 3: Substitute into SOLUTION:

7.2 SOLVING LINEAR SYSTEMS BY SUBSTITUTIONPRACTICE 2: Solve the linear system

STEP 1: Solve for one variable: I will solve for x in : STEP 2: Substitute into and solve for x:

3+𝑦

HOMEWORK #2:

Pg. 439: 4-24 even, 31

If finished, work on other assignments:

HW #1: Pg. 430: 3-10, 12-15, 22, 23, 32