Which expression can be written as  5 ⋅ ( 2 + 7 )? a) 5 * 2+7 b) 5 - (2+7) c) (5*2) + (5*7) d) (5+2) + (5+7)

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