When you change a standard form into a vertex form, a number is added and subtracted as part of a process. e. g. (x² + 6x + 9 - 9) -4. Explain why this process is called “completing the square”

I’m not big brain

Step-by-step explanation:

the formula of a slope:

from a table we have

substitute:

the slope of f(x) is -1.

the graph of funcfion g(x) is a horizontal line. the slope of a horizontal line is equal 0. therefore the slope of g(x) is 0.

-1 < 0