Objective: Solving systems of linear equations by graphing

System of linear

equation

System of linear

equation

two or more linear equations

How do I solve linear systems of equations?

How do I solve linear systems of equations?

any ordered pair (point) that makes ALL the equations true

solutionsolution

1. graph the equations

2. Find the point of intersection

*** point of intersection is a solution ***

example

xy

xy

4

5

Graph the following equations and find the solution. Check your answer.

0 1

4

4

5 1

1

5

bm

xy

bmxy

bm

xy

bmxy

Objective: Solving systems of linear equations by graphing (real-world problems)

How do I solve

problems using linear systems of equations?

How do I solve

problems using linear systems of equations?

1. Define variables

2. Write equations

3. Graph equations

4. Find solution

example

Suppose you have $55 in your bank account. You start saving $10 each week. Your friend has $20 in her bank account and is saving $15 each week. When will you and your friend have the same amount of money in your accounts?

STEP 1 define variables

Let w = time for accounts to be equal

Let z = money account

example

Suppose you have $55 in your bank account. You start saving $10 each week. Your friend has $20 in her bank account and is saving $15 each week. When will you and your friend have the same amount of money in your accounts?

STEP 2 Write equations

2015

5510

wz

wz your account

friend’s account

STEP 3 Graph equations

2015

5510

wz

wz

Solution: 7 weeks