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
(-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