-4.5+6 and 2/7

=3/2+2/7

=25/ 14

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

= 1- 1

=0

5.6+(-0.9)+4.4+(-8. 1)+(-0. 1)

= 10- 1-8. 1

=0.9

(+66)+(- 12)+( 1 1.3)+(-7.4)+(+8. 1)+(-2.5)

=66- 12+ 19.4-9.9

=63.4-9.9

=53.5

(+3 and 2/5)+(-2 and 7/8)+(-3 and 65438+5/02)+(- 1 and 1)+(+5 and 3/5)+(+5 and 65438+5/02)

=9-4+2

=7

You can ask if you don't understand. If it helps, remember to adopt it.

Thank you, I wish you progress in your study!