Think About the Process Use the algebra tiles to help you solve the equation 4x - 12 = 20. What is the first step in solving the equation using algebra tiles? What is the solution to the equation?

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