Question

The trinomial x2 – 3x – 4 is represented by the model. What are the factors of the trinomial?

Answer 1

Answer:

$(x+1)$ and $(x-4)$.

Step-by-step explanation:

We have been a trinomial $x^2-3x-4$. We are asked to find the factors of our given trinomial.

We will use split the middle term to solve our given problem. We need to two number whose sum is $-3$ and whose product is $-4$. We know such two numbers are $-4\text{ and }1$.

Split the middle term:

$x^2-4x+x-4$

Make two groups:

$(x^2-4x)+(x-4)$

Factor out GCF of each group:

$x(x-4)+1(x-4)$

$(x-4)(x+1)$

Therefore, factors of our given trinomial are $(x+1)$ and $(x-4)$.

Answer 2

x^2 – 3x – 4 = (x - 4)(x +1 )
cause
(x - 4)(x +1 ) = x^2 - 4x + x - 4 = x^2 - 3x - 4

answer
 (x - 4)(x +1 ) are factors of x^2 – 3x – 4