Algebra 2 HELP PLEEZ!!?

Question

These are mah problems,I am clueless.....HOW? "^"carrot means exponent! "/" equals fraction/division.

#1 V= 3.14/3 r^2h,solve for h #2 S=L(1 - r) ,solve for r

Solve for x

#3 4/9 (x + 3) = g

#15 1/2 (x - 3) + (3/2 - x) = 5x

#18 u/5 + u/10 - u/6 = 1


I am so lost,If you can make any since of any of these please explain,thanky!

Answer 1

1. h = 3*V/(3.14*r^2)

2. S = L - Lr
...Lr = L - S
...r = (L-S)/L
...r = 1 - S/L

3. 4/9x + 4/3 = g
...4/9x = g - 4/3
...x = 9/4(g - 4/3)
...x = 9/4g - 3

15. 1/2x - 3/2 + 3/2 - x = 5x
...-1/2x = 5x
...Only solution is x = 0
...(check to make sure you copied the equation correctly)

18. u/5 + u/10 - u/6 = 1
...6u/30 + 3u/30 - 5u/30 = 1
...4u = 30
...u = 15/2

Answer 2

#1 V = (3.14 r^2h)/3 so 3V = (3.14r^2)h, and h = (3V)/(3.14r^2)
#2 S = L(1 - r), so S/L = 1 - r, and r = 1 - S/L
#3 (4/9) (x + 3) = g, so x + 3 = (9/4)g, and x = (9g)/4 - 3
#15 (1/2)(x - 3) + (3/2 - x) = 5x
(1/2)x - 3/2 + 3/2 - x = 5x
-1/2 x = 5x
-x = 10x, so 0 = 11x, and x = 0
#18 u/5 + u/10 - u/6 = 1
LCM(5, 10, and 6) = 30
30(u/5) + 30(u/10) - 30(u/6) = 30(1)
6u + 3u - 5u = 30
4u = 30, so u = 15/2

Answer 3

Are you wanting direct answers, or worked out answers? I can do them in my head and find the answer, but schools want them worked out.