Step 1: 2x[3`x`^{2} - 20`x` +28] Factor out anything common to all terms.

Step 2: 2`x`[3`x`^{2}+(-20)x +28] Write trinomial in standard form a`x`^{2}+ bx + c

Step 3: 2`x`[3`x`^{2}+(-20)x + (-28)]

Step 4: List all pairs of factors of a-c If a*c is negative, then factors have opposite signs. If ac is positive, then factors have same signs. Sign of b determines sign of factors. Factors of 84 are: -1, -84 -4,-21 -6,-14 -7, -12 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 2`x`[3`x`^{2} +(-6)x + (-14)x + (-28)]

Step 6: Factor out something common to first two terms.
2`x` [3`x`^{2} +(-6)`x` + (-14)`x` + (-28)] -- 2`x`[3`x`(x-2) + (-14)x + (-28)]

Step 7: Factor out same binomial in last two terms.
2`x`[3`x`(x-2) + (-14)(x-2) ]

Step 8: Apply Distributive Law and convert trinomial into the product of two binomials and a monomial.
2`x`[(3x-14)(x-2)] -- 2`x`(3x-14)(x-2) This is the answer.