X^2 + 20x + 28 = 9 find the graphing/vertex form

Step-by-step explanation:

For a quadratic equation, the vertex form is given by : , where (h, k) is the vertex.

The given quadratic equation:

Subtract 9 from both sides

compare this to , and add both sides

b= 20

  [(b/2)²=20/2=10]

So, the vertex form :

correct answer:

i^31 = -i

  or  

step-by-step explanation:

if the four friends split the cost, p, of the pizza evenly, then each friend pays one-fourth of the cost of the pizza.

the expression is   or