EXAMPLE 1 Add and subtract matrices Perform the indicated operation, if possible. 3 0 –5 –1 a. –1 4 2 0 + 3 + (–1) 0 + 4 –5 + 2 –1 + 0 = = 2 4 –3 –1 –2 5 3 –10 –3 1 7 4 0 –2 –1 6 b. – 7 – (–2) 4 – 5 0 – 3 –2 – (–10) –1 – (–3) 6 – 1 = 9 –1 –3 8 2 5 =

EXAMPLE 2 Multiply a matrix by a scalar Perform the indicated operation, if possible. a. 4 –1 1 0 2 7 –2 –2(4) –2(–1) –2(1) –2(0) –2(2) –2(7) = –8 2 –2 0 –4 –14 = b. 4 –2 –8 5 0 –3 8 6 –5 + 4(–2) 4(–8) 4(5) 4(0) –3 8 6 –5 = + –8 –32 20 0 –3 8 6 –5 = +

EXAMPLE 2 Multiply a matrix by a scalar –8 + (–3) –32 + 8 20 + 6 0 + (–5) = –11 –24 26 –5 =

GUIDED PRACTICE for Examples 1 and 2 Perform the indicated operation, if possible. + –2 5 11 4 –6 8 1. –3 1 –5 –2 –8 4 ANSWER –5 6 6 2 –14 12

GUIDED PRACTICE for Examples 1 and 2 –4 0 7 –2 –3 1 2 2 –3 0 5 –14 2. – ANSWER –6 –2 10 –2 –8 15

GUIDED PRACTICE for Examples 1 and 2 3. 2 –1 –3 –7 6 1 –2 0 –5 – 4 ANSWER –8 4 12 28 –24 –4 8 0 20

GUIDED PRACTICE for Examples 1 and 2 4 –1 –3 –5 –2 –2 0 6 4. 3 + ANSWER 3 –3 –2 1

GUIDED PRACTICE for Examples 1 and 2