Answer:
A) (3x + 21)(x + 7)
Step-by-step explanation:
If we look at the equation we can see that it is a quadratic equation, therefore we can factor it in the following way...
[tex]3x^{2} + 42x + 147 = 3x^{2} + 21x + 21x + 147 = 3x(x + 7) + 21(x + 7) = (3x + 21)(x + 7)[/tex]
Therefore the answer is A)
