Determine whether the sequences given below form arithmetic progressions, and the next three numbers in the sequence. Then
identify the common difference. 4,0,-4,-8,-12,

If you are looking for the formula it is an=a1+d(n-1) and to solve it it is an=-4n+8

Step-by-step explanation:

∠acb = 8°

step-by-step explanation:

∠xba lies on the circle and is half the measure of the intercepted arc ax

hence

measure of arc ax = 2 × 42° = 84°

∠acb is outside the circle and is

∠acb = (arcab - arcax ), hence

∠acb = 0.5 (100 - 84) = 0.5 × 16° = 8°