Khan academy data distribution stuff pls help

Radii ok and nl are perpendicular to om because of the radius-tangent theorem. by definition of perpendicular, angles kom and lnm are right angles. this means that triangles kom and lnm are right triangles. angle lmn is common to both right triangles, so by the triangles kom and lnm are similar.

What is the product of the radical expression. (7-2square root) (8+2 square root)

Solve -2(4y + 6) = 52. 5 -5 8 -8 and !