Question

The factorization of x2 + 3x – 4 is modeled with algebra tiles.

What are the factors of x2 + 3x – 4?
(x + 4) and (x – 4)
(x + 3) and (x – 4)
(x + 4) and (x – 1)
(x + 3) and (x – 1)

Answer 1

x² + 3x - 4

factors of x² are x * x
factors of -4 that will result to a +3

4 * -1 = -4
4 - 1 = 3

(x + 4) and (x - 1)

x(x-1) + 4(x-1)
x² - x +4x - 4
x² + 3x - 4

Answer 2

The quadratic trinomial can be factor using the following formula:

`ax^2+bx+c=a(x-x_1)(x-x_2), \text{ where } x_1,\ x_2 \text{ are trinomial roots}`.

1. For the quadratic trinomial
`x^2 + 3x - 4` find the roots:

`image`.

2. The factoring form of trinomial is

`x^2+3x-4=(x+4)(x-1)`.

3. The factors are x+4 and x-1

Answer: correct choice is C.