答案:E
解析:
When 3 is subtracted from x, the result is x-3. The square root of this difference is square root (x-3). When 5 is added to square root (x-3), the final result is 9. This can be written as (square root (x-3)) plus 5 = 9. Subtracting 5 from both sides gives the equation square root (x-3) = 4. Squaring both sides of this equation gives x-3 = 16, or x = 19.