A portion of the Quadratic Formula proof is shown. Fill in the missing reason.

Statements
Reasons
ax2 + bx + c = 0
Given
ax2 + bx = −c
Subtract c from both sides of the equation

Divide both sides of the equation by a

Complete the square and add to both sides

Square on the right side of the equation

Find a common denominator on the right side of the equation

Add the fractions together on the right side of the equation

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Rewrite the perfect square trinomial as a binomial squared on the left side of the equation
Take the square root of both sides of the equation
Multiply both sides of the equation by 2
Square the left side of the equation