9514 1404 393
Answer:
(x +6)(3x +4)
Step-by-step explanation:
The usual approach to this is to look for factors of the product 3·24 that have a sum of 22.
72 = 1·72 = 2·36 = 3·24 = 4·18 = 6·12 = 8·9
Sums of these factor pairs are 73, 38, 27, 22, 18, 17.
Now, you can rewrite the expression splitting the middle term into two parts:
3x² +4x +18x +24
x(3x +4) +6(3x +4) . . . . . . factor by grouping
(x +6)(3x +4) . . . . . . . . . . your factored form
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Additional comment
I find this method easiest to explain and to do without error. There are various "X" methods in which you write the product at the top (3·24) and the sum at the bottom (22), then fill in the sides with the factors having that product and sum (4, 18). When the leading coefficient is not 1, there are methods added to this that get you to the correct factors.
One such method is to use the leading coefficient inside parentheses: (3x+4)(3x+18) Then divide that product by the leading coefficient:
(3x +4)(3x +18)/3 = (3x +4)(x +6).
In some cases, each of the binomials needs to be divided by part of the leading coefficient; not the whole thing, as here.
