#### Answer

Chapter 6 - Section 6.3 - Exercise Set: 88 (Answer)
(c) is a factored form of $4x^2 + 19x + 12$, and (a), (b) and (d) are not.

#### Work Step by Step

Chapter 6 - Section 6.3 - Exercise Set: 88 (Solution)
For (a), (2x + 4)(2x + 3), the sum of $2x\cdot3$ + $4\cdot 2x$ = $14x$ and $\neq$ 19x;
For (b), (4x + 4)(x + 3), the sum of $4x\cdot3$ + $4\cdot x$ = $16x$ and $\neq$ 19x;
For (c), (4x + 3)(x + 4), the sum of $4x\cdot4$ + $3\cdot x$ = $19x$ and equal to 19x;
For (d), (2x + 2)(2x + 6), the sum of $2x\cdot6$ + $2\cdot 2x$ = $16x$ and $\neq$ 19x;
Thus, (c) is a factored form of $4x^2 + 19x + 12$, and (a), (b) and (d) are not.