How do you find the y-intercept of a line given two ordered pairs?

In the diagram below? p is circumscribed about quadrilateral abcd. what is the value of x

An ulcer medication has 300 milligrams in 2 tablets. how many milligrams are in 3 tablets?

In the given triangle, ∠aed ∼ ∠ abc, ad = 6.9, ae = 7.2, de = 5.2, and bc = 10.2. find the measure of bd and ce. round your answer to the nearest tenth.