\"\"

\

The arithmetic sequence is \"\".

\

The nth term of an arithmetic sequence is \"\"

\

Here \"\" = First term of the sequence, d = common difference.

\

The sequence three arithmetic means between \"\" and 7.

\

\"\"

\

\"\"                (Substitute \"\")

\

\"\"                 (Substitute \"\")

\

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

\

Apply addition property of equality: a = b then \"\".

\

\"\"               (Add 8 to each side)

\

Apply commutative property of addition: \"\".

\

\"\"

\

\"\"                              (Apply additive inverse property: \"\")

\

\"\"                                  (Add: 7 + 8 = 15)\"\"

\

Apply division property of equality: a = b then \"\".

\

\"\"                             (Divide each side by 5)

\

\"\"                                  (Cancel common term)

\

d = 3                                       (Divide: \"\")\"\"

\

\"\"

\

\"\"

\

\"\"

\

\"\"

\

\"\"

\

\"\"

\

\"\"\"\"

\

The arithmetic means are \"\".