Algebra: A Combined Approach (4th Edition)

$7x^{2}$ + 9x + 2 = (7x + 2)(x+ 1)
The first factor of $7x^{2}$ + 9x + 2 is given $\rightarrow$ (7x + 2). Thus, the other factor's first term should be x since the first term in the trinomial is $7x^{2}$. Note 7x(x) = $7x^{2}$. Also, the last term of the trinomial is 2. This means that 1 should be multiplied to the "2" in (7x + 2) to yield the "2" in the trinomial. Thus, (x + 1) should be the other factor.