How do you evaluate 8-20+(-39)-(-12)+13-48?

2 Answers
Mar 6, 2018

color(blue)(-74)

Explanation:

8 - 20 + (-39) - (-12) + 13 - 48

=> 8 - 20 - 39 + 12 + 13 - 48 Removing the braces.

=> 8 + 12 + 13 - 20 - 39 - 48 Rearranging terms.

=> (8 + 12 + 13 ) - (20 + 39 + 48) Grouping terms according to sign.

=> 33 - 107 = - 74

Mar 6, 2018

-74

Explanation:

A -number and +number make -.
A -number and -number make +.
A +number and +number make +.

Knowing these rules, we can simplify the equation.
8 − 20 + ( − 39 ) − ( − 12 ) + 13 − 48 ->
8 − 20 − 39 + 12 + 13 − 48

Following PEMDAS, add first.
8 − 20 − 39 + (12 + 13) − 48 ->
8 − 20 − 39 + 25 − 48

Subtract.
8 − 20 − 39 + 25 − 48 ->
-12 − 39 + 25 − 48 ->
-51 + 25 − 48 ->
-99 + 25

Add.
-99 + 25 = -74