Solve the formula for rje indicated variable w=a-k/m for a

Find the length of the following tangent segments to the circles centered at o and o' whose radii are 5 and 3 respectively and the distance between o and o' is 12. what is the tangent segment of cd?

Which is the equation of an ellipse with directrices at x = ±4 and foci at (2, 0) and (−2, 0)?

If p(a) = 0.70 and p(b) = 0.20, then a and b are independent events if