Step 1: 2x [ 3x2 - 20x + 28 ] Factor out anything common to all terms.
Step 2: 2x [ 3x2 + (-20)x + 28 ] Write trinomial in standard form ax2 + bx + c
Step 3: 2x [ 3x2 + (-20)x + 28 ] Determine product of a * b = 3 * 28 = 84
Step 4: List all pairs of factors of a*c. If a*c is negative, then factors have opposite signs.
If a*c is positive, then factors have the same signs. Sign of b determines sign of factors.
Factors of 84 are: -1, -84 -4, -21 -6, -14 -7, -21
Select factor pair such that their sum is b term = -20
Step 5: Split middle term b order factors as multiple of the a and c terms
2x [ 3x2 + (-6)x + (-14)x + 28 ]
Step 6: Factor out something common to first two terms.
2x [ 3x2 + (-6)x + (-14)x + 28 ] → 2x [ 3x(x - 2) + (-14)x + (-14)x + 28 ]
Step 7: Factor out the same binomial in last two terms.
2x [ 3x(x - 2) + (-14)(x-2)
Step 8: Apply Distributive Law and convert trinomial into the product of two binomials and a monomial.
2x [(3x - 14) (x - 2)] → 2x(3x - 14)(x - 2) This is the answer.