Final answer:
The value of the given expression is -275.
Step-by-step explanation:
The value of the given expression A = x - (x^2 + 3).
Substituting the given value of x into the expression, we have:
A = 17 - (17^2 + 3)
A = 17 - (289 + 3)
A = 17 - 292
A = -275
Therefore, the value of the expression is -275.