(3.8)-(+7) (-5.9)—(6. 1)

(+2/5)-(-3/5) (-2/5)—(-3/5)

1/2- 1/3 (- 1/2)- 1/3

-4.2+5.7-8.4+ 10 - 1/4+5/6+2/3+ 1/2

12-(- 18)+(-7)- 15 4.7-(8.9)-7.5+(-6)

Mathematical rational number addition and subtraction process and answer should have. urgent