9514 1404 393
Answer:
a, d
Explanation:
We assume you want factors that use real integers.
a) 121x² +36y² . . . . cannot be factored using real numbers
b) (4x +4)(x +1) = 4(x +1)²
c) x(x² -4) = x(x -2)(x +2)
d) x⁴ -15n³ +12n² . . . . cannot be factored*
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* If the polynomial is n⁴ -15n³ +12n², then it factors as n²(n² -15n +12).