Factor 5 out of 5x^2
5(x^2) + 20x + 30
Factor 5 out of 20x
5(x^2) + 5(4x) + 30
Factor 5 out of 30
5x^2 + 5 (4x) + 5 * 6
Factor our of 5x^2 + 5(4x)
5(x^2 + 4x) + 5 * 6
Factor 5 out of 5(x^2 + 4x) + 5 * 6
5(x^2 + 4x + 6)
The GCF = 5
Your answer is: C. 5