From the sum of 3a-b+9 and b-9, subtract 3a-b-9

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?

Two streets intersect at a 30- degree angle. at the intersection, the are four crosswalks formed that are the same length. what type of quadrilateral is formed by the crosswalks?

Four congruent circular holes with a diameter of 2 in. were punches out of a piece of paper. what is the area of the paper that is left ? use 3.14 for pi