select the correct answer.\nwhat is the completely factored form of this expression?\n3x² - 17x - 28\n\na…

Answer:

B. $(3x + 4)(x - 7)$

Explanation:

Step1: Multiply the coefficient of $x^{2}$ and the constant term

$3\times(- 28)=-84$

Step2: Find two numbers that multiply to -84 and add up to -17

The numbers are -21 and 4 since $-21\times4=-84$ and $-21 + 4=-17$

Step3: Rewrite the middle - term

$3x^{2}-21x+4x - 28$

Step4: Group the terms

$(3x^{2}-21x)+(4x - 28)$

Step5: Factor out the greatest common factor from each group

$3x(x - 7)+4(x - 7)$

Step6: Factor out the common binomial factor

$(3x + 4)(x - 7)$