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X2 + 4x – 9

Can someone give me step by explanation for this vertex form question and write the equation in vertex form?

2 Answers

6 votes

Answer:

y=(x+2)^2−13

Explanation:

Set the polynomial equal to y to find the vertex form.

y=x^2+4x−9

Complete the square for x^2+4x−9

Use the form ax^2+bx+c , to find the values of a, b, and c.a=1,b=4,c=−9

Consider the vertex form of a parabola. a(x+d)^2+e

Substitute the values of a and b into the formula d= b/2a.

d= 4/2(1)

Cancel the common factor of 4 and 2.

d=2

Find the value of e using the formula e=c− b2/4a.

e=−13

Substitute the values of a, d, and e into the vertex form a(x+d)^2+e.

(x+2)^2−13

Set y equal to the new right side.

User Rabbott
by
6.1k points
2 votes

Answer:

6x-9

Explanation:

2x+4x=6x

add the -9 at the end

thats all

User Ild Flue
by
6.6k points