Question

Evaluate -2[7 - 3(-8 + 5)]

Answer 1

Apply PEMDAS

Evaluate everything in parentheses first beginning with the inner most parentheses:
So first perform the operation -8 + 5 what do you get?

Answer 2

-3

Answer 3

Okay, so now you have -2[7 - 3(-3)]

or to make it more clear, you're left with \(-2[7 - 3 \times -3]\)

So you have a product and a multiplication within the grouping symbols. According to PEMDAS, which operation do you think should be performed first: Multiplication or Subtraction?

Answer 4

Multiplication

Answer 5

Correct and what do we multiply?

Answer 6

-2 x 7-3

Answer 7

Actually, we need to deal with what is within the grouping symbols. The only thing you need to focus on is this expression for now: \(7 - 3 \times -3\)

Answer 8

Knowing this, what operation do we perform?

Answer 9

7-3 x -3 = 16 x -2 = -32 witch is one of the answers.

Answer 10

Here is where we are so far:
$$\displaystyle \begin{array}{ l c }
=-2[ 7\ -\ 3( -8\ +\ 5)] & \mathbf{Given}\\
=-2[ 7\ -\ 3( -3)] & \mathbf{Add\ -8\ and\ 5}\\
=-2[ 7\ -\ 3\ \times \ -3] & \mathbf{-3( -3) \ is\ the\ same\ as\ -3\ \times \ -3} \ \\
& \\
&
\end{array}$$

Answer 11

All you have to do is just perform the next operation which is \(-3 \times -3\)
For now, don't worry about what the answer choices are just yet. That's a distraction for you atm.

Answer 12

-3 x -3 is just 9

Answer 13

Exactly. So now we have -2[7 + 9]

Answer 14

What do we do next?

Answer 15

Keep in mind what is inside the grouping symbols always has priority.

Answer 16

7+9

Answer 17

Yes what is 7 + 9?

Answer 18

16 -.-

Answer 19

What operation is that?

Answer 20

times -2

Answer 21

Whoops my bad

Answer 22

We have -2[16] sorry.

Answer 23

And what is the final answer now?

Answer 24

Again -32

Answer 25

Correct. But this time we have done the proper steps to get to the -32

Answer 26

Thank you

Answer 27

You're welcome. Just remember to do the inside operations before you do the outside operations.