Question 1/10 points) Which expression is equivalent to x2 - 4x – 45?
0
(x– 9) (x - 5)
Oь
(x + 9) (x + 5)
Оe
(x + 9) (x - 5)
Od
(x - 9) (x + 5)
Can somebody please help me with 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