Answer:
(k +2j)(4k -j)
Step-by-step explanation:
Multiply the first and last coefficients to find their product:
(4)(-2) = -8
Factor this product until you find factors that have a sum of +7. Since you want a positive sum, it works well to start with small negative factors.
-8 = -1×8 . . . . these have the desired sum: (-1) +(8) = +7
Now, rewrite the middle term using these factors:
4k² -jk +8jk -2j²
Factor each pair of terms
k(4k -j) +2j(4k -j)
Recognize these new terms have a common factor, and factor that out:
(k +2j)(4k -j) . . . . . the factorization you're looking for
