Answer:
(5 x + 2) (x + 2)
Explanation:
Factor the following:
5 x^2 + 10 x + 2 x + 4
10 x + 2 x = 12 x:
5 x^2 + 12 x + 4
Factor the quadratic 5 x^2 + 12 x + 4. The coefficient of x^2 is 5 and the constant term is 4. The product of 5 and 4 is 20. The factors of 20 which sum to 12 are 2 and 10. So 5 x^2 + 12 x + 4 = 5 x^2 + 10 x + 2 x + 4 = 2 (5 x + 2) + x (5 x + 2):
2 (5 x + 2) + x (5 x + 2)
Factor 5 x + 2 from 2 (5 x + 2) + x (5 x + 2):
Answer: (5 x + 2) (x + 2)