Presented by: Mr. Joseph C. Nilo

Simplify the fol lowing

1.(-2) + (-3)

2.(-6) + 5

3.(3) + (-3)

4. (-2) – (-3)

5. (-6) – (5)

6. (3) – (-3)

Problem of the day!!! Find two numbers whose sum and

difference are the following:Sum Difference Answer

5 1 3 and 2

5 3 4 and 1

-2 0 -1 and -1

-2 -12 -7 and 5

System of Linear Equation & their Solution A pair of equation of the form

Ax + By = C

Dx + Ey = FWhere A, B, D, and E are not equal to zero is

called a system of linear equation in two variables

An ordered pair (x , y) is a solution set of the system of linear equations which satisfies both of the equation

Illustrative Example Determine whether (-1, 2) is a solution

of 3x + y = - 1 and 2x + 4y = 8

Solution:

* 3x + y = - 13(-1)+(2) = - 1

- 3 + 2 = - 1 - 1 = - 1

* 2x + 4y = 8

2(-1) + 4(2) = 8

- 2 + 8 = 8

6 ≠ 8

Although (1, 2) makes the first sentence / equation true it does not satisfy the second and therefore it can’t be accepted as a solutions of the system

Determine whether (2, -3) is a solution of 2x + 2y = -2 and 3x + 2y = 0

* 2x + 2y = - 22(2)+2(-3) = - 2

4 - 6 = - 2 - 2 = - 2

* 3x + 2y = 0

3(2) + 2(-3) = 0

6 - 6 = 0

0 = 0 The pair (2, -3) makes both equation

true so it is a solution of the system

Activity: Cooperative Learning Write (√) whether the ordered pair beside

each system is a solution and (X) if not a solution of the system.

• (4, 8) ; x + 2y = 20 3x – 4y = 12

• (5, - 4) ; 4x + 3y = 8 x + y = 1

• (0, 2) ; x + y = 2 x = 0

√

X

√

Communicating Skil lsWhen do we say that a

given pair of real numbers is a solution

of the system?

Test Proper Write (√) whether the ordered pair

beside each system is a solution and (X) if not a solution of the system

• (5, -1) ; 2y + x = 5 3y + 4x = - 19

• (½ , 3) ; 4x + 8y = 26 6x - 2y = - 3

X

√

AssignmentA. Answer the following

List 5 ordered pairs which satisfy the equation x + y = 6

List 5 ordered pairs which satisfy the equation x – y = 8

What is ordered pair that satisfies both equations in number 1 and 2

B. Bring the following: Each group 10 pcs. Graphing Paper 5 pcs Color Pen (Different color) Ruler