A portion of the quadratic formula proof is shown. Fill in the missing statement.

Statements Reasons
x squared plus b over a times x plus the quantity b over 2 times a squared equals negative 4 times a times c all over 4 times a squared plus b squared over 4 a squared Find a common denominator on the right side of the equation
x squared plus b over a times x plus the quantity b over 2 times a squared equals b squared minus 4 times a times c all over 4 times a squared Add the fractions together on the right side of the equation
the quantity x plus b over 2 times a squared equals b squared minus 4 times a times c all over 4 times a squared Rewrite the perfect square trinomial on the left side of the equation as a binomial squared
x plus b over 2 times a equals plus or minus the square root of b squared minus 4 times a times c, all over 4 times a squared Take the square root of both sides of the equation
x plus b over 2 times a equals plus or minus the square root of b squared minus 4 times a times c, all over 2 times a Simplify the right side of the equation
? Subtract the quantity b over 2 times a from both sides of the equation
x equals b plus or minus the square root of b squared minus 4 times a times c, all over 2 times a
x equals negative b plus or minus the square root of b squared minus 4 times a times c, all over a
x equals negative b plus or minus the square root of b squared minus 4 times a times c, all over 2 times a
x plus b over 2 times a equals negative b plus or minus the square root of b squared minus 4 times a times c, all over 2 times a

x equals negative b plus or minus the square root of b squared minus 4 times a times c, all over 2 times a