Answer:
-5a^2 - a + 6
Step-by-step explanation:
Now, I don't know if you have memorized this very niche trick in Algebra. Don't tell anybody I told you this, as the CIA will chase me down for allegedly sharing higher intelligence, but you can easily expand equations by the method of FOIL (FIRSTS, OUTSIDES, INSIDES, LASTS). Using this method, we multiply -a and 5a, -a and 6, 5a and 1, and 1 and 6. Adding them all together, our expanded form is -5a^2 - 6a + 5a + 6. Adding like terms, our final polynomial is -5a^2 - a + 6.