Question

Refer to Expression 1 and Expression 2.

Expression 1

6⋅7−32⋅9+43
6⋅7−32⋅9+43



Expression 2

5+4⋅2+6−2⋅2−1
+⋅+−⋅−



What is the value of Expression 1?

Insert parentheses in Expression 2 so that it has a value of 19. Then show why your expression has a value of 19.

Answer 1

Expression 1

6 ⋅ 7 - 32 ⋅ 9 + 43

= 42 - 288 + 43

= -246 + 43

= -203

Expression 2

Insert parentheses around 5 + 4:

(5 + 4) · 2 + 6 - 2 ⋅ 2 - 1

= 9 · 2 + 6 - 2 ⋅ 2 - 1

= 18 + 6 - 4 - 1

= 24 - 4 - 1

= 20 - 1

= 19

Explanation:

Answer 2

Use the order of operations PEMDAS:

• Parentheses
• Exponents
• Multiplication and Division (from left to right)
• Addition and Subtraction (from left to right)

Expression 1

6 ⋅ 7 - 32 ⋅ 9 + 43

= 42 - 288 + 43

= -246 + 43

= -203

Expression 2

Insert parentheses around 5 + 4:

(5 + 4) · 2 + 6 - 2 ⋅ 2 - 1

= 9 · 2 + 6 - 2 ⋅ 2 - 1

= 18 + 6 - 4 - 1

= 24 - 4 - 1

= 20 - 1

= 19