Can y’all help me on this please

Look at the following graph of the given equation. determine whether the equation is a function. explain why or why not.

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

Y= 4x + 3 y = - 1 4 x - 5 what is the best description for the lines represented by the equations?