As part of a science experiment, Sam recorded the four values shown in the table, but one of them got smudged on his paper. He remembers that the sum of the trials was βˆ’1. What was the value that was smudged?

Trials

βˆ’9

12

(smudged)

βˆ’8


A) 2


B) βˆ’2


C) βˆ’4


D) 4


PLEASE HELP IM GONNA FAIL!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! :(

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Respuesta :

Answer:

D) 4

Step-by-step explanation:

βˆ’9 + 12 + (unknown) + βˆ’8 = βˆ’1

Start by going through and testing each option

βˆ’9 + 12 + 2 + βˆ’8 =

3 + 2 + βˆ’8 =

5 + βˆ’8 =

βˆ’3

βˆ’3 β‰  βˆ’1

A) 2 is not possible.

βˆ’9 + 12 + βˆ’2 + βˆ’8 =

3 + βˆ’2 + βˆ’8 =

1 + βˆ’8 =

βˆ’7

βˆ’7 β‰  βˆ’1

B) βˆ’2 is not possible.

βˆ’9 + 12 + βˆ’4 + βˆ’8 =

3 + βˆ’4 + βˆ’8 =

βˆ’1 + βˆ’8 =

βˆ’9

βˆ’9 β‰  βˆ’1

C) βˆ’4 is not possible.

From this, D is looking like the answer. But to be sure, test it.

βˆ’9 + 12 + 4 + βˆ’8 =

3 + 4 + βˆ’8 =

7 + βˆ’8 =

βˆ’1

βˆ’1 = βˆ’1

D) 4 is the answer.