Question

What is (-18.278) - (-6.8)

Answer 1

(-18.278) - (-6.8) { first we have to open parenthesis or brackets of the equation }
-18.278 + 6.8 { - + - = + }
then we have to add both numbers and we get 
-11.478 Ans

(-18.278) - (-6.8) = -11.478 Ans

Answer 2

Do not add subtract a negative add
-18.278+6.8
it's a negative and positive so subtract the larger absolute value from the smaller absolute value and keep the sign.
-18.278+6.8