Question #N439
Which of the following expressions is equivalent to $(x^2+3)(x^2-3)$?
A. x^4-6
B. x^4-9
C. x^4+6
D. x^4+9
Correct Answer is: B
This expression is in the form of the 'difference of squares' pattern: (a + b)(a - b) = a^2 - b^2. In this case, a = x^2 and b = 3. Therefore, the expression simplifies to (x^2)^2 - 3^2 = x^4 - 9.