Question

Inga is solving 2x2 + 12x – 3 = 0. Which steps could she use to solve the quadratic equation? Select three options. 2(x2 + 6x + 9) = 3 + 18 2(x2 + 6x) = –3 2(x2 + 6x) = 3 x + 3 = Plus or minus StartRoot StartFraction 21 Over 2 EndFraction EndRoot 2(x2 + 6x + 9) = –3 + 9

Answer 1

1. 2(x2 + 6x + 9) = 3 + 18

2. 2(x2 + 6x) = 3

Let's take a look at the first choice:

2(x² + 6x + 9) = 3 + 18

Now, we will multiply 2 with every member of the other multiplier on the left side:

2·x² + 2·6x + 2·9 = 3 + 18

2x² + 12x + 18 = 3 + 18

2x² + 12x - 3 = 18 - 18

2x² + 12x - 3 = 0

Let's take a look at the second choice:

2(x² + 6x) = 3

Now, we will multiply 2 with every member of the other multiplier on the left side:

2·x² + 2·6x = 3

2x² + 12x = 3

2x² + 12x - 3 = 0

I hope it helps and that you have a great day! :)

Answer 2

1, 3, 4

Explanation:

You want to identify the steps used to solve the quadratic equation ...

2x² +12x -3 = 0

Solution

Solving the quadratic by completing the square uses these steps.

2x² +12x = 3 . . . . . . . . . . separate the constant from the x-terms

2(x² +6x) = 3 . . . . . . . . . . factor out the leading coefficient (choice 3)

2(x² +6x +9) = 3 +18 . . . . add the square of 6/2 (choice 1)

2(x +3)² = 21 . . . . . . . . . . simplify

(x +3)² = 21/2 . . . . . . . . . . divide by 2

x +3 = ±√(21/2) . . . . . . . . . take the square root (choice 4)

x = -3 ±√(21/2) . . . . . . actual solution