Yvonne is solving the quadratic equation 6x2 + 24x + 7 = 0 by completing the square. Her first four steps are shown in the table.

In which step did Yvonne first make an error?

Step 1

Step 2

Step 3

Step 4

Step 1 should be

Bring the constant to the other side and divide the whole equation with 6 resulting to

x2 + 4x = - 7/6

Step 3 should be

Complete the square by dividing the coefficient of x by 2, squaring it and adding the result to both sides of the equation.

x2 + 4x + 4 = - 7/6 + 4

Step 4 should be

Factor the quadratic equation and simplify

(x+2) 2 = - 17/6

Step should be

Get the square root of booth sides and solve for the values of x

x+2 = + - √ (102) / 6

So,

x = - 2 + √ (102) / 6 and x = - 2 - √ (102) / 3