21:20
In which step did Yvonne first make an error?
Yvonne is solving the quadratic equation 6x2 + 24x + 7 = 0
by completing the square. Her first four steps are shown in
the table.
Yvonne's Work
Step 1
Step 2
Step 3
Step 4
Step 1
Step 2
6x² +24x+7-0
6x² +24x - 7
6(x²+4x) -7
6(x²+4x+4) - 3+24
6(x+2)²-27
Step 3
Step 4
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Answer:

Step 2

Step-by-step explanation:

Given the quadratic equation  6x² + 24x + 7 = 0, the following steps must be followed when finding the roots using the completing the square method.

Step 1: Subtract 7 from both sides

6x² + 24x + 7 - 7= 0 -7

6x² + 24x = -7

Step 2: divide through by the coefficient of x²

6x²/6 + 24x/6 = -7/6

x² + 4x = -7/6

Step 3: Add half of the coefficient of x (i.e 4/2 = 2) to both sides of the equation to complete the square of the equation x² + 4x.

x² + 4x + 2= -7/6 + 2

(x+2)² = -7/6 + 2

(x+2)²  = 5/6

Step 4: taking the square root of both sides

√(x+2)²  = √5/6

x+2 = ±√5/6

x = -2±√5/6

x = -2+√5/6 and -2-√5/6

Based on the conclusion above, it can be seen that Yvonne made the first error in step 2. Yvonne suppose to divide through by the coefficient of x² (i.e 6)