\"\"

\

The side lengths of a right triangle are \"\" ; \"\"

\

Apply Pythagorean theorem: \"a

\

\"\"                      (Substitute 7 for a and 9 for c)

\

\"\"                    (Evaluate powers: \"\")\"\"

\

\"\"    (Subtract 49 from each side)

\

\"\"                            (Subtract: \"\")

\

\"\"                     (Take square root to each side)

\

\"\"                (Write \"\")

\

 \"\"            (Product property of square roots: \"square)

\

\"\"                          (Cancel squares and roots)\"\"

\

The unknown length \"\".