For 15 points you have to explain and write the answer for 5 questions. don't write random answers and incorrect answers explain clearly.

Solve for the indicated variable

6. a+3/b = c for a

8. Formula for the area of a triangle

a = 1/2bh for b

11. formula for the area of a trapeziod

A = 1/2 (a+b)h for a

12. Formula for the volume of a cylinder

V = πr^2 h for r

13. Janet earns $300 per week plus a commission of 10% on all sales that she makes. Write a formula for E, Janet's weekly earnings, in terms of s, her sales for the week. Then solve your formula for s.