Question

what is the final simplified form of the product ((x - 4)(x + 5))?

a. (x^2 + 5x - 4x)

b. (x^2 - 20)

c. (x^2 - x - 20)

d. (x^2 + x - 20)

Explanation:

Step1: Apply FOIL method

$(x-4)(x+5) = x\cdot x + x\cdot5 -4\cdot x -4\cdot5$

Step2: Calculate each term

$= x^2 + 5x -4x -20$

Step3: Combine like terms

$= x^2 + (5x-4x) -20 = x^2 + x -20$

Answer:

d. $x^{2}+x-20$