Algegra
posted by G .
Diving Radicals
Using \/ for radical sign
7 / \/X
This book has been confusing me.
The book gives the answer 7\/X / X.
Isn't the answer 7X?

When I took algebra many many years ago they called this rationalization of the denominator. For some reason, mathematicians don't seem to like to leave fractions with a sqrt sign in the denominator. This is how you get it out.
7/(sqrt x) =
multiply by sqrt x/sqrt x to obtain
7*(sqrt x)/(sqrt x)*(sqrt x) =
7*(sqrt x)/x. 
Simplify. Write each answer in scientific notation.
1) (5.86 × 100
)(7.99 × 100
)