If ` x : y = 1 : 2` , then the value of the ratio `(x + 2y) : (2x + 9y)` is -

(a) If x : y = 3 : 4 , then find the value of the ratio (2x + y) : ( 9x - 2y) . (b) If x : y = 5 : 4 , then find the value of the ratio (x^(2) + xy) : (x^(2) - xy) .

If x-y=9 and xy=16 then the value of x^(2)+y^(2)

If x:y =2 :3 then the value of {:(3x+2y)/(9x+5y):} will be:

If 2x+3y=8 and x y=2 , find the value of 4x^2+9y^2