If the set a {x | x + A / x2-4 = 1} is a single element set, then the value set of a is m= The teacher's answers were 2, - 2, - 17 / 4, but I wrote - 17 / 4 and - 4, X + a divided by the square of x minus 4 equals 1

If the set a {x | x + A / x2-4 = 1} is a single element set, then the value set of a is m= The teacher's answers were 2, - 2, - 17 / 4, but I wrote - 17 / 4 and - 4, X + a divided by the square of x minus 4 equals 1

(x + a) / (x ^ 2-4) = 1 (x + a) = (x ^ 2-4) = (X-2) (x + 2) a = 2 X-2 = 1 x = 3 satisfies the condition a = - 2 x + 2 = 1 x = 1 satisfies the condition when a is not equal to 2 or - 2, (x + a) / (x ^ 2-4) = 1 (x + a) = (x ^ 2-4) x ^ 2-x - (a + 4) = 0
b^2-4ac=0 1+4(a+4)=0 1+4a+16=0 4a=-17 a=-17/4