Please someone help me with this... and please thouroughly explain, i have no clue what to do.

What is the slope of the equation y =

Abag contains 4 red, 7 blue and 5 yellow marbles. event a is defined as drawing a yellow marble on the first draw and event b is defined as drawing a blue marble on the second draw. if two marbles are drawn from the bag, one after the other and not replaced, what is p(b|a) expressed in simplest form? a. 7/16 b. 7/15 c. 14/16 d. 14/15

X^2/100+y^2/25=1 the length of the major axis is: a)5 b)10 c)20