Question

When trying to solve an equation I'm getting stuck on a step.
Rewrite equation in vertex form.
y=x^2+4x+3
x^2+4
b/2=4/2=2
x^2+4+(2)^2=x^2+4+4
Now i'm stuck is the next line
y=x^2+4x+4-4+3 or y=x^2+4x+4+3-4

Answer 1

\(\bf y=x^2+4x+4+3-4\implies y=(x^2+4x+4)+3-4\\ \quad \\
y=(x^2+4x+2^2)-1\implies y=(x+2)^2-1\)