Respuesta :
This is a notable trinomial.
You have to find two numbers which summed give 1 and multiplied give 20.
In this case +4 and -5
-5+4 = -1(a)
-5*4 = -20
So (a+4)(a-5)
You have to find two numbers which summed give 1 and multiplied give 20.
In this case +4 and -5
-5+4 = -1(a)
-5*4 = -20
So (a+4)(a-5)