Answer:
H = 20
Explanation:
Looks like you got everything correct. Nice!
For your last one, let's get H by itself. Since 1/2 is division, let's multiple it by 2 to turn it into one. Because you multiply by 2 on the left side, you have to on the right side also...
(1/2)(2) = 1
(1)(h) = h
On the other side, 10(2) = 20.
Combining the 2, H = 20