if x+y=9 and (x-y)exponent 2=25 but y has to be bigger than x what would be x and what would be y

Using the first equation, we have y =9-x

Substituting this into the second equation, we have

(x - (9-x))^2 = 25    Simplifying we have

(2x -9)^2 = 25       Expaand this on the left

4x^2 -36x + 81 = 25    Subtract 25 from both sides

4x^2 - 36x + 56 = 0    Factor, if possible

(4x -8) ( x -7) = 0     setting each factor to 0, we get

x = 2    and x =7    And using x + y = 9

y = 7    and y = 2     But since y > x. then 

(2, 7) is the solution