Algebra 2 Adding and Subtracting Matrices

Algebra 2 The table shows information on ticket sales for a new movie that is showing at two theaters. Sales are for children (C) and adults (A). Lesson 4-2 Adding and Subtracting Matrices Theater C A C A Matinee Evening a. Write two 2  2 matrices to represent matinee and evening sales. Theater Theater Matinee C A Theater Theater Evening C A Additional Examples

Algebra 2 (continued) Lesson 4-2 Adding and Subtracting Matrices b. Find the combined sales for the two showings = = Theater Theater C A Additional Examples

Algebra 2 Find each sum. Lesson 4-2 Adding and Subtracting Matrices a.b. 9 0 – –8 –5 1 + –3 8 5 –1 = – = 3 + (–3) –8 + 8 – (–1) = 9 0 –4 6 = 0 Additional Examples

Algebra 2 A = and B =. Find A – B. Method 1: Use additive inverses. Lesson 4-2 Adding and Subtracting Matrices 4 8 –2 0 7 –9 4 5 A – B = A + (–B) = –2 0 –7 9 –4 –5 Write the additive inverses of the elements of the second matrix. 4 + (–7) –2 + (–4) 0 + (–5) Add corresponding elements = –3 17 –6 –5 = Simplify. Additional Examples

Algebra 2 (continued) Method 2: Use subtraction. Lesson 4-2 Adding and Subtracting Matrices A – B = – 4 8 –2 0 7 – – 7 8 – (–9) –2 – 4 0 – 5 Subtract corresponding elements = –3 17 –6 –5 = Simplify. Additional Examples

Algebra 2 Adding and Subtracting Matrices Find each sum or difference –12 –9 6 6 –5 – –5 4 –3 – –6