Answer:
f(x) = (3x -2)(2x +1)
Explanation:
The procedure for factoring expression of the form ...
ax² +bx +c
is to look for factors of a·c that have a sum of b.
The product a·c is 6·(-2) = -12. You are looking for factors that have a sum of b = -1. From your familiarity with multiplication tables, you know ...
-12 = 1(-12) = 2(-6) = 3(-4)
The sums of the factor pairs in this list are -11, -4, -1. So, the last pair of factors, {3, -4} is the one we're looking for.
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At this point, there are several ways to proceed. Perhaps the simplest is to rewrite the linear term as the sum of terms involving these factors:
-x = 3x -4x
f(x) = 6x² +3x -4x -2
Now, the expression can be factored 2 terms at a time:
f(x) = (6x² +3x) -(4x +2) . . . . . pay attention to signs
f(x) = 3x(2x +1) -2(2x +1) . . . . factor each pair
f(x) = (3x -2)(2x +1) . . . . . . . . factor out the common factor of (2x+1)