ĐKXĐ: -3 ≤ x ≤ 3
Ta có √25 − x^2 − √9 − x^2 = 2
<=> √25 − x^2 = 2 + √9 − x^2
<=> (√25 − x^2)^2 = (2 + √9 − x^2)^2
<=> 25 - x^2 = 4 + 4.√9 − x^2 + 9 - x^2
<=> 12 - x^2 = 4.√9 − x^2 - x^2
<=> 12 = 4.√9 − x^2
<=> √9 − x^2 = 3
<=> 9 − x^2 = 9 <=> x^2 = 0 <=> x = 0
Vậy x = 0