How do i solve these? thanx in advance

7. Subtract 5.7 from both sides to get the variable on one side. (f=2)
8. Subtract 5.52 from both sides to get the variable on one side. (f=5)
9. Add 3.77 to both sides so the variable will be on one side. 
10. Add 10.58 to both sides.
11. Divide by 2.2 on both sides. 2.2b/2.2 will leave you with the variable b. 8.8/2.2=4; b=4.
12. Divide by 2.5b on both sides. 2.5b/2.5 leaves b. 10/2.5= 4; b=4.

7) minus 5.7 from both sides to get
f=1

8) minus 5.52 from both sides to get
f=5

9) add 3.77 to both sides to get
f=11.1

10) add 10.58 to both sides to get
f= 21

11) divide both sides by 2.2 to get
b=4

12) divide both sides by 2.5 to get
b=4

hope this helps!