How do I work out x2 + 9x+ 18 = (??)(x+6) ?

@zugedanit (1958)
Philippines
February 16, 2007 9:10am CST
How do I work out x2 + 9x+ 18 = (??)(x+6) ?
2 responses
@AJMSmith (113)
17 Feb 07
Let the unknown factor be ax + b. Then (ax + b)(x + 6) = ax^2 + (6a+b)x + 6b. Since we know this equals x^2 + 9x + 18, a=1 b=3 (=18/6) as a check 6*1+3=9. The other factor is x+3.
• Indonesia
16 Feb 07
There someone asking to solve their math homework. Wow it's cool so maybe i want to ask about something more difficult. the answer of this question is x^2 + 9x + 18 = ()(x+6) (x+3) (x+6) = ()(x+6) then eliminate (x+6) () = (x+3) easy right