Expression in simplest form (3x^2 + 4x - 8) - (-2x^2 + 4x + 2)

8000 + 8800 + 8000 + 8 million + 80 trillion + another a katrillion equals

How do you solve a question like this?

Which sum or difference identity would you use to verify that cos (180° - q) = -cos q? a.) sin (a -b) = sin a cos b – cos a sin b b.) cos (a -b) = cos a cos b – sin a sin b c.) cos (a -b) = cos a cosb + sin a sin b d.) sin (a + b) = sin a cos b + cos a sin b