Respuesta :
He set the factored expressions equal to each other. instead of setting them equal to zero
What are quadratic equations?
The name Quadratic comes from "quad" meaning square because the variable gets squared (like x2). It is also called an "Equation of Degree 2
The given solution of the quadratic equation in the question is
[tex]f(x) = x^2 + 4x + 3.[/tex]
His work is shown below.
[tex]0 = x^2 + 4x + 3[/tex]
[tex]0 = (x + 3)(x + 1)[/tex]
Here is where we use the zero product property
x+3 = 0 x+1 =0 We do not set them equal to each other
Hence He set the factored expressions equal to each other. instead of setting them equal to zero
To know more about quadratic equations follow
https://brainly.com/question/472337