1. WARM UP 3
WRITING EQUATIONS Write in slope-intercept form the equation of the line that passes through the given point and has the given slope. (Lesson 5.2, 5.3)
(-2, 4), m = 3
(5, 1), m = 5

2. WARM UP 2
WRITING EQUATIONS Write in slope-intercept form the equation of the line that passes through the given point and has the given slope. (Lesson 5.2, 5.3)
(-2, 4), m = 3
(5, 1), m = 5

3. WARM UP 1
WRITING EQUATIONS Write in slope-intercept form the equation of the line that passes through the given point and has the given slope. (Lesson 5.2, 5.3)
(-2, 4), m = 3
(5, 1), m = 5

4. WARM UP
WRITING EQUATIONS Write in slope-intercept form the equation of the line that passes through the given point and has the given slope. (Lesson 5.2, 5.3)
(-2, 4), m = 3
(5, 1), m = 5

5. 7.3 Linear Combinations Solve by Linear Combinations
EXAMPLE 3
Solve by Linear Combinations
Solve the linear system
x – 3y = 30 EQUATION 1
3y + x = 12 EQUATION 2
SOLUTION
① ARRANGE the equations with like terms in columns.

6. 7.3 Linear Combinations Solve by Linear Combinations
EXAMPLE 3
Solve by Linear Combinations
Solve the linear system
x – 3y = 30 EQUATION 1
3y + x = 12 EQUATION 2
SOLUTION
②ADD the equations.

7. 7.3 Linear Combinations Solve by Linear Combinations
EXAMPLE 3
Solve by Linear Combinations
Solve the linear system
x – 3y = 30 EQUATION 1
3y + x = 12 EQUATION 2
SOLUTION
③ SUBSTITUTE 21 for x into either equation and solve for y.
ANSWER> The solution is (21 , -3)

8. 7.3 Linear Combinations CHECK POINT 3x + 2y = 8 2y = 12 – 5x
Solve the linear system by Linear Combination.
3x + 2y = 8
2y = 12 – 5x
2x + 5y = -11
5y = 3x -21
4x + 7y = -9
3x = 3y + 18
CHECK POINT