Write the expression ^4sqrta^3-b^3 without radicals, using only positive exponents

1. are the triangles similar and if so why? what is the value of x? show your work.

What is the axis of symmetry of the function f(x)=-(x+ 9)(x-21)

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