How do I express this as a quadratic in standard form

(-a+1) (5a+6)

Standard form is ax + by = c

(-a+1) (5a+6) distribute.

-a times 5a = - 5a^2, - a times 6 = - 6a

1 times 5a = 5a, 1 times 6 = 6

Then write it out properly.

-5a^2 - 6a + 5a + 6 = 0

Then combine like terms.

-6a + 5a = - a

So the answer is - 5a^2 - a + 6

(1 - a) • (5a + 6) is the answer