What is the explicit formula for this sequence? -9, -3,3,9,15, O A. 6,= (-9) + (0-1)(-6)
O B. ,= 6 + (n-1)(-9)
O C. an = 21 + (n-1)6
O D. a,= (-9) + (1 - 1)6​

In the first triangle 80+20+p=180 (since sum of all angles of a triangle is 180)so p= 80also in second triangle 55+45+q=180 (since sum of all angles of a triangle is 180)so q=80so we can conclude that p=80 degrees q=80 degrees so p=q=80 degreeshence option b is correct