=- 18-(-47) (first calculate the number in brackets, negative minus positive is negative, which is -47).

=- 18+47 (burden reduction, converted into negative number+positive number)

=29

(-3 1)-(- 14+3.4)-(-2.5+4.6)

= (-31)-(-10.6)-2.1(the number in brackets is counted first here), (-14+3.4 negative number plus positive number, which is greater is positive or negative,-14.

=-31+10.6-2.1(to reduce the negative number, it is-31+10.6-2.1).

=-20.4-2. 1

=-22.5 (negative negative positive negative)

6.6-7 and two thirds -(-4 and two fifths +8 and one third)

6.6- 7 2/3- (-4 2/5+8 1/3)

=6.6- 7 and 2/3-(-4 and 6/ 15+8 and 5/ 15) (here, the numbers in brackets are calculated first, and the denominator is the same, that is, the denominator is 15, that is, the numerator is multiplied by multiple, that is, the above formula).

=6.6- (7 2/3)-(3 14/ 15)

=( 6 and 9/ 15)-(7 and 10/ 15)-(3 and 14/ 15) (all are reduced to the same denominator, and the numerator is multiplied by the above formula).

=- 1 and115-3 and 14/ 15.

=-5

-2 and 2/5-(3/5+3 and 4/ 1 1)-(- 1 and 3/1)

-2 and 2/5-(3/5+3 and 4/ 1 1)-( 1 and 3/1)

= -2 and 2/5-(33/55+3 and 20/55)+1 and 3/1(here, the numbers in brackets are calculated first and become the same denominator; Other burden reduction is positive)

= -2 2/5- 3 53/55+ 1 3/ 1 1

=-2 22/55-3 53/55+13/11(converted to the same denominator)

= -6 and 4/ 1 1+ 1 and 3/1(here -2 and 22/55-3 and 53/55= -5 and 75/55 = -6 and 20/.

= -5 and111

Above ~