28. -1/3=r-3/4
Move -3/4 to the other side. Sign changes from -3/4 to +3/4
-1/3+ 3/4=r-3/4+3/4
-1/3+3/4=r
Find the common denominator for both of the fractions which is 12. Multiply by 4 for -1/3. Multiply by 3 for 3/4.
-1/3(4)+3/4(3)= -4/12+9/12= 5/12
33. -5/6+c=-11/12
c=-11/12+5/6
Find the common denominator which is 12 for 5/6. Multiply by 2. 5*2=10, 6*2=12
c=-11/12+10/12=-1/12
34. s-1/9=5/18
s-1/9+1/9=5/18+1/9
Find the common denominator which is 18. Mutiply by 2 for 1/9 . 1*2=2, 9*2=18
s=5/18+2/18=7/18
Answers:
28. 5/12
33. -1/12
34. 7/18