Pls answer im dying here

Which equations represents circles that have a diameter of 12 units and a center that lies on the y-axis? check all that apply

After being rearranged and simplified, which of the following equations could be solved using the quadratic formula? check all that apply. a. 9% + 3x2 = 14 + x-1 b. -x+ + 4x + 7 = -32-9 c. 5x + 4 = 3x4 - 2 d. 2x2 + x2 + x = 30

What are the measures of ∠a, ∠b, ∠c and ∠d? explain how to find each of the angle measure.