Question

Which equation represents the vertex form of the equation y = x² + 2x - 6?

y = (x + 2)² -
y = (x + 1)2 - 6
y = (x + 2)²-7
y = (x + 1)²-7

Answer 1

Explanation:

Steps

1] On the right, put brackets around the 1st 2 terms.

y = (x^2 + 2x) - 6

2] Divide the second term's coefficient by 2 and square the result.

2/2 = 1

3] Square the result

1^2 = 1

4] Add that inside the brackets

y = (x^2 + 2x + 1) - 6

5] Subtract 1 outside the brackets. The original equation is still there.

y = (x^2 + 2x + 1) - 6 - 1

y = (x^2 + 2x + 1) - 7

6] What is inside the brackets is a perfect square.

y = (x + 1)^2 - 7

Answer D