Algebramedium · Past Paper
Factorize a^4 - 81.
A(a-3)(a+3)(a^2+9)
B(a-9)(a+9)
C(a^2-9)^2
D(a-3)^2(a+3)^2
✓ Correct Answer: A — (a-3)(a+3)(a^2+9)
(a^2)^2 - 9^2 = (a^2-9)(a^2+9) = (a-3)(a+3)(a^2+9).
Share this question
✓ Correct Answer: A — (a-3)(a+3)(a^2+9)
(a^2)^2 - 9^2 = (a^2-9)(a^2+9) = (a-3)(a+3)(a^2+9).
Share this question