Question

Your friend asks you to check their work. You see the expression (8−10)2−30÷5×6+2 simplified in the following way:

Original Problem: (8−10)2−30÷5×6+2
Step 1: (−2)2−30÷5×6+2
Step 2: 4−30÷5×6+2
Step 3: 4−30÷30+2
Step 4: 4−1+2
Step 5: 3+2
Step 6: 5
Part A: Explain, using complete sentences, in which step and what specifically your friend's error was.



Part B: Correctly simplify this expression using a similar format - showing work for each step like was done above. Full credit will only be given if work shows Step 1, Step 2, Step 3, etc. as seen above.

Answer 1

-38

Explanation:

He is not following the correct sequence:

Simplify the following:

(8 - 10) 2 - 30/5×6 + 2

-30/5×6 = (-30×6)/5:

(8 - 10) 2 + (-30×6)/5 + 2

30/5 = (5×6)/5 = 6:

(8 - 10) 2 - 6×6 + 2

8 - 10 = -2:

-2×2 - 6×6 + 2

-2×2 = -4:

-4 - 6×6 + 2

-6×6 = -36:

-4 + -36 + 2

-4 - 36 + 2 = 2 - (4 + 36):

2 - (4 + 36)

| 1 |

| 3 | 6

+ | | 4

| 4 | 0:

2 - 40

2 - 40 = -(40 - 2):

-(40 - 2)

| 3 | 10

| |

- | | 2

| 3 | 8:

Answer: -38