Factor completely 5x2 – 5x – 100

a)5(x + 4)(x – 5)
b)5(x – 2)(x + 10)
c)(5x + 20)(x – 5)
d)(5x – 10)(x + 10)

The equation given in the question is

5x^2 - 5x - 100 = 5x^2 - 25x + 20x - 100
                         = 5x(x - 5) + 20(x - 5)
                         = (5x + 20)(x - 5)

From the above deduction, it can be easily concluded that the correct option among all the options that are given in the question is the third option or option "C". I hope that this is the answer that you were looking for and the answer has actually come to your desired help.