Question

In factoring by grouping, what would you have for step 3 for the following?

Step 1: x^3 +5x^2 +4x+20
Step 2: x^2 (x+5)+4(x+5)
Step 3: ?

Answer 1

Step 3: (x^2 + 4)(x + 5)

Explanation:

Step 1: x^3 +5x^2 + 4x+20

Step 2: x^2 (x+5) + 4(x+5)

Step 3: (x^2 + 4)(x + 5)

Answer 2

Factor out the x+5

(x+5)(x^2+4)

Explanation:

Step 1: x^3 +5x^2 +4x+20

Step 2: x^2 (x+5)+4(x+5)

Step 3: Factor out the x+5

(x+5)(x^2+4)