68.6k views
3 votes
Factorise completely: 9x2 + 42x + 49

User Ben Cox
by
8.2k points

2 Answers

1 vote

Answer:

i think the answer is (3x + 7)(3x + 7)

Explanation:

User Joel Cochran
by
8.3k points
3 votes
This is a perfect square trinomial:
9 x² + 42 x + 49 = ( 3 x )² + 2 · 3 x · 7 + 7² =
= ( 3 x + 7 )² = ( 3 x + 7 ) · ( 3 x + 7 )
User JMAA
by
7.9k points