Question 419340
In {{{(-5+6x^7+2x^5) + (9x^7+5x^5+9)}}} you will need to add "like terms", that is, terms where the exponent is the same.  You have two terms with exponent of 7, two terms with exponent 5 and two terms with no exponent.

Rearranging so that we have "like terms" together, we get:
{{{6x^7 + 9x^7 + 2x^5 + 5x^5 - 5 + 9}}}

Combining "like terms" gives us the answer:
{{{15x^7 + 7x^5 + 4}}}