Factor completely: 9x2 + 42x + 49

(3x + 7)(3x − 7)

(9x − 7)(9x − 7)

(3x + 7)(3x + 7)

(9x + 7)(9x + 7)

Question

Factor completely: 9x2 + 42x + 49

 (3x + 7)(3x − 7)

 (9x − 7)(9x − 7)

 (3x + 7)(3x + 7)

 (9x + 7)(9x + 7)

anonymous · Answer

$$9x^2 + 42x + 49$$

so the first term is: $9x^2 $
   Then you know: 
    $3 \times 3 = 9$
     $$x \times x = x^2 $$ 
so: $$(3x) \times (3x) = 9x^2 $$

anonymous · Answer

following?

anonymous · Answer

Therefore, choices B and D are right away crossed out as a correct possible answer choice.

anonymous · Answer

notreally

mertsj · Answer

Use FOIL on each one of your answers and see which one works.

anonymous · Answer

yes ^ that also works, it is like working backwards if you do not really understand what i was talking about.