Please help me find the last two steps, ik the first ones are givens but i need help with the others.

Ineed solving this problem h/8=-25 solve for h idk how to this can someone show me and also give an answer you

1. evaluate 8x(2)y9(-2) for x=-1 and y=2 2. simplify the equation. -() 3. simplify the expression. [tex]\frac{5}{x(-2) y9(5)}[/tex]

Acertain volume of water contains 100000 hydrogen atoms and 50,000 oxygen atoms how many hydrogen atoms are in a volume of water containing 4 million oxygen atoms