Question 887290
15n^2+6n^3-3n^3-5n^2-3n^2-5n^4
<pre>
<font color="red">15n<sup>2</sup></font><font color="blue">+6n<sup>3</sup>-3n<sup>3</sup></font><font color="red">-5n<sup>2</sup>-3n<sup>2</sup></font>-5n<sup>4</sup>

The red terms are like terms, which combine to <font color="red">+7n<sup>2</sup></font>

The blue terms are like terms, which combine to <font color="blue">+3n<sup>3</sup></font>

The black term -5n<sup>4</sup> is not like any other term.

In descending powers, we start with the black term, since it
has the largest exponent. Then the term with 3 exponent, and
finally the term with the 2 exponent

-5n<sup>4</sup>+3n<sup>3</sup>+7n<sup>2</sup>

Edwin</pre>