Solve each quadratic equation by using the method of completing the square. Match each equation with the corresponding solution.
-$x = 9 , x = 11$
A) $x ^ { 2 } - 14 x = - 48$
B) $x ^ { 2 } - 20 x = - 99$
C) $x ^ { 2 } - 8 x = - 7$

Question

Solve each quadratic equation by using the method of completing the square. Match each equation with the corresponding solution.
-$x = 9 , x = 11$ 
A) $x ^ { 2 } - 14 x = - 48$ 
B) $x ^ { 2 } - 20 x = - 99$ 
C) $x ^ { 2 } - 8 x = - 7$

Quizplus · Accepted Answer

To complete the square for each equation:
A) $x^2-14x=-48$
$x^2-14x+49=-48+49$
$(x-7)^2=1$
$x-7=\pm \sqrt{1}$
$x=7\pm 1$
$x=8,6$
B) $x^2-20x=-99$
$x^2-20x+100=-99+100$
$(x-10)^2=1$
$x-10=\pm \sqrt{1}$
$x=10\pm 1$
$x=11,9$
C) $x^2-8x=-7$
$x^2-8x+16=-7+16$
$(x-4)^2=9$
$x-4=\pm \sqrt{9}$
$x=4\pm 3$
$x=7,1$
Therefore, the only equation that matches the given solutions is B with $x=11,9$.

Solve Each Quadratic Equation by Using the Method of Completing x=9,x=11x = 9 , x = 11x=9,x=11

Solve Each Quadratic Equation by Using the Method of Completing $x = 9 , x = 11$