EXAMPLE 1 Following Order of Operations Music You buy a used guitar for $50. You then pay $10 for each of five guitar lessons. The total cost can be found by evaluating the expression Is the total cost $100 or $300 ?
= EXAMPLE 1 To find the guitar costs described, evaluate First multiply 10 and 5. = 100 Then add 50 and 50. ANSWER The total cost is $100. Following Order of Operations
EXAMPLE 2 Evaluating a Variable Expression Substitute 25 for x and 2 for y. Evaluate the power. Multiply 8 and 3. = 1 Subtract 24 from 25. x 3y 3 – = 25 3(2 3 ) – = 25 3(8) – = – Evaluate x 3y 3 when x = 25 and y = 2. –
GUIDED PRACTICE for Examples 1 and 2 Evaluate the expression ANSWER – 12 ANSWER ANSWER
GUIDED PRACTICE 4. Evaluate a + 4b 2 when a = 6 and b = ANSWER for Examples 1 and 2