Question

Which expression is equivalent to this polynomial? 9x² +4 OA. (3x+21)(3x-21) OB. (3x+2)(3x - 2) OC. (3x+21)² OD. (3x + 2)²​

Answer 1

None of these

Explanation:

None of this expressions are equivalent. But if the original polynomial is 9x^2-4, then answer would be (3x+2)(3x-2).

Using formula (a+b)(a-b)=a^2-b^2 , it follows:

(3x+2)(3x-2)=(3x)^2-2^2=9x^2-4