How do I simplify the expression

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

X2 + y 2 = 36 x + y = 6 solve the system of equations.

Two variables, x and y, vary inversely, and x=12 when y=4. what is the value of y when x=3?