1. Drill #18* Evaluate the following absolute value expressions If x = – 6 1.3x + 2 2.– 2x – 8 3.-2 3 – x

2. 2 – 3 Adding and Subtracting Integers Objective: To find the absolute value of a number, and to add and subtract integers. HW 2-3 pg 90-91, #26 – 60 (even) Copy problems, show work. HEADING, TITLE, and OBJECTIVE!

3. Adding Integers **(9.) 9. Adding Integers: To add integers with the same sign, add their absolute values. The result keeps the original sign. To add integers with different signs, subtract the smaller absolute value from the bigger absolute value. The result gets the same sign as the integer with the bigger absolute value.

4. Find each sum #18* 4. -10 + (-17) 5. 39 + (-22) 6.-28 + 16 7. 15 + -33

5. Additive Inverse Property **(10.) 10. Additive Inverse Property: For every number a, a + (-a) = 0 An additive inverse of a number, is its negative value. What is the multiplicative inverse of a number?

6. Classwork (#18*) Find the additive inverse of the following: 10. 18 11. - ½

7. Subtracting Integers **(11.) 11. Subtracting Integers: To subtract a number, add its additive inverse. For any numbers a and b, a – b = a + (-b)

8. Find each difference (#18)* 10. 6 – 14 11. -6 – 14 12.-12 – (-8) 13. 43 – (-26)

9. Matrices ** (12.) 12.matrix: A rectangular arrangement of elements in rows and columns. Example: Matrices are defined by braces. You can add and subtract matrices of the same dimensions.

10. Adding and Subtracting Matrices To add and subtract matrices they must be the same dimension (they must have the same number of rows and columns.) Add or subtract elements in the same position: Adding: Subtract:

11. Classwork (#18*) Add and subtract the following matrices: 12. 13.

12. Using matrices to group information Gahanna Lincoln High School Example, page 88

13. Rewind When adding integers of the same sign you … When adding integers of opposite signs … Turn all subtraction into ? … An additive inverse is ?... To add and subtract matrices they must be ?...