X square + 3xy-4 (y) square = 0 find x + y =? X-Y =? Y is not 0

X square + 3xy-4 (y) square = 0 find x + y =? X-Y =? Y is not 0

(x-y)(x+4y)=0
If X-Y = 0
x=y=0
And Y is not zero
So x + 4Y = 0
x=-4y
therefore
x+y=-3y
x-y=-5y

Ask two questions. General score: (x + 4) / (x ^ 2-8x + 15), (x + 5) / (x ^ 2 + X-12) and (x-3) / (x ^ 2-x-20)
Ask two questions
General division: (x + 4) / (x ^ 2-8x + 15), (x + 5) / (x ^ 2 + X-12) and (x-3) / (x ^ 2-x-20)
Approximately: (9a ^ 2 + 24ab + 16b ^ 2) / (3a + 4b)

1. (x + 4) / (x-3) (X-5); (x + 5) / (x + 4) (x-3); (x-3) / (X-5) (x + 4); general score: 1
（x+4)^2/(x-3)(x+4)(x-5) ; ;(x^2-25)/(x+4)(x-3)(x-5);(x-3)^2/(x-3)(x+4)(x-5)
2.(3a+4b)^2/(3a+4b)=3a+4b

Two out of five and three out of seven points

10/35,15/35