Students were asked to write 6 ex to the power of 5. plus 8 ex minus 3 ex to the power of 3. plus 7 ex to the power of 7. in standard form. Shown below are four student responses. Ann: 8 ex minus 3 ex to the power of 3. plus 6 ex to the power of 5. plus 7 ex to the power of 7.
Bob: negative 3 ex to the power of 3. plus 6 ex to the power of 5. plus 7 ex to the power of 7. plus 8 ex,
Carrie: 8 ex plus 7 ex to the power of 7. plus 6 ex to the power of 5. minus 3 ex to the power of 3.
Dylan: 7 ex to the power of 7. plus 6 ex to the power of 5. minus 3 ex to the power of 3. plus 8 ex.

Which student is correct?