Respuesta :

Let's begin with moving the constant to the side with f(x):
f(x) - 7 = x² + 10x

Next let's add (half of 10)² to both sides of the equation: btw that is 25 but on the right side we will leave it as 5² because it will make the factoring easier

f(x) - 7 + 25 = x² + 10x + 5²

Lets simplify the left side a bit and factor the perfect square trinomial on the right.

f(x) + 18 = (x + 5)²

Finally move the constant back to the side with the binomial

f(x) = (x + 5)² - 18

The vertex is (-5, -18)

Using the completing-the-square method the vertex form of the function

f(x)  =  x²  +  10x  +  7 is f(x)  =  (x  +  5)²  -  18

The given function is:

f(x)  =  x²  +  10x  +  7

Comparing f(x)  =  x²  +  10x  +  7 with f(x) = ax² + bx + c

a  = 1,  b = 10,  c  = 7

(b/2)²  =  (10/2)²  =  5²

Add and subtract 5² to the right hand side of the equation

f(x)  =  x²  +  10x + 5² +  7 - 5²

f(x)   =  x²  +  10x  +  5²  +  7 - 25

f(x)   =  x²   +  10x  +  5²  - 18

f(x)  =  (x  +  5)²  -  18

f(x)  =  (x  +  5)²  -  18 is of the form f(x) = a(x - h)² + k which is the vertex form of a quadratic equation

Therefore, the vertex form of the function f(x)  =  x²  +  10x +  7 is

f(x)  =  (x  +  5)²  -  18

Learn more here: https://brainly.com/question/19105786