Respuesta :

Answer:

5a^2 + 4a - 9 = (5a + 9)(a - 1)

Step-by-step explanation:

The given expression is 5a^2 + 4a - 9

The leading coefficient is 5 and last term is -9

Multiply them, we get -45

Now find the factors of -45 such that when you add the factors we have to get 4.

9*-5 = -45

9 + (-5)= 4

The right factors are 9 and -5.

5a^2 + 4a - 9 = 5a^2 + 9a - 5a - 9

= 5a^2 - 5a + 9a - 9

= 5a(a -1)+9(a-1)

= (5a +9)(a-1)

The missing factor is (a -1)

Thank you.