The first three steps for solving the quadratic equation by completing the square are shown. Fill in the missing number in the last step. 9x2 +54x = 7 9(x2 + 6x) = 7 9(x2 + 6x + 9) = 7 + 88

Answer:[tex]x= \sqrt{88}/3-3[/tex] will be the last step.Explanation : Given quadratic equation 9x^2+54x=7⇒ [tex]9(x^2+6x)=7[/tex]( By the associative property)⇒[tex]9(x^2+6x)+81=7+81[/tex] ( by adding 81 on both sides)⇒[tex]9(x^2+6x+9) = 88[/tex] (taking 9 as common in left side of equation.)⇒[tex]9(x+3)^2=88[/tex] ⇒[tex](x+3)^2=88/9⇒ x+3=\sqrt{88/9}[/tex] ⇒[tex]x=\sqrt{88/9}-3\impliesx= \sqrt{88}/3-3[/tex]