7. 1) -(b+2) +(a-5) -(c-b) = -b - 2 + a - 5 - c + b = -(-3(1/8)) - 2 + 26 - 5 - 19 + (-3(1/8)) = 3(1/8) - 2 + 26 - 5 - 19 - 3(1/8) = 25/8 - 2 + 26 - 5 - 19 - 25/8 = -2+26-5-19= 0

2) -(m+3) +(n-4) -(p-m) = -m-3+n-4-p+m= 2(2/9) -3+28-4-21-2(2/9) =28-21-4-3= 0

8. 1) 4,8-(x-5,2) = -14,1

4,8 -x+ 5,2= -14,1

10-x= -14,1

14,1-10=x

x= 4,1

2) 3,7 -(x-6,3) = -16,2

3,7 - x+6,3= -16,2

16,2-3,7= x

x=12,5

9. 1) 10/16 -16/10= 50/80 - 128/80= (-78/80)÷2= -39/40

2) 10/18 - 18/10=50/90 - 162/90= (-112/90)÷2= -56/45= -1(11/45)