7.1 - 7.3 Review

General

100

Name the three methods used for solving linear systems.

Graphing, Substitution, Elimination

200

What is the first step of substitution?

Pick one equation and solve for one variable.

300

When using the elimination method, what do you do if no variables are eliminated when the equations are combined?

Use multiplication on one equation

400

When using the graphing method to solve linear systems, how do you know where the solution is?

The solution is the point where the two lines intersect.

Graphing

100

y = x + 1

y = 2x + 1

x = 0, y = 1

200

y = 2/3x - 1

y = -3x - 1

x = 0, y = -1

300

y = -2/3x + 2

y = 2/3x - 2

x = 3, y = 0

400

y - x = 1

y + 2x = 4

x = 1, y = 2

Substitution

100

x + y = 7

2x + y = 10

x = 3, y = 4

200

−5x + y = −2

−3x + 6y = −12

x = 0, y = -2

300

−5x + y = −3

3x − 8y = 24

x = 0, y = -3

400

2x + y = 20

6x − 5y = 12

x = 7, y = 6

Elimination

100

x + y = 12

x - y = 0

x = 6, y = 6

200

x + 3y = 1

−3x − 3y = −15

x = 7, y = -2

300

-4x + y = 6

-5x - y = 21

x = -3, y = -6

400

−3x − 4y = 2

3x + 3y = −3

x = -2, y = 1

Choose the best method!

100

y = 2x + 1

y = -3x + 1

Graphing

200

a + b = 10

a - b = 2

Elimination

300

x + 2y = 5

2x + 3y = 8

Substitution

400

10x + 3y = 13

-10x + 4y = -6

Elimination