$x = \dfrac { \color{#FF6800}{ - } \left ( \color{#FF6800}{ - } 7 \right ) \pm \sqrt{ \left ( - 7 \right ) ^ { 2 } - 4 \times 1 \times \left ( - 120 \right ) } } { 2 \times 1 }$
$ $ Simplify Minus $ $
$x = \dfrac { 7 \pm \sqrt{ \left ( - 7 \right ) ^ { 2 } - 4 \times 1 \times \left ( - 120 \right ) } } { 2 \times 1 }$
$x = \dfrac { 7 \pm \sqrt{ \left ( \color{#FF6800}{ - } \color{#FF6800}{ 7 } \right ) ^ { \color{#FF6800}{ 2 } } - 4 \times 1 \times \left ( - 120 \right ) } } { 2 \times 1 }$
$ $ Remove negative signs because negative numbers raised to even powers are positive $ $
$x = \dfrac { 7 \pm \sqrt{ 7 ^ { 2 } - 4 \times 1 \times \left ( - 120 \right ) } } { 2 \times 1 }$
$\color{#FF6800}{ x } = \color{#FF6800}{ \dfrac { 7 \pm \sqrt{ 7 ^ { 2 } - 4 \times 1 \times \left ( - 120 \right ) } } { 2 \times 1 } }$
$ $ Organize the expression $ $
$\color{#FF6800}{ x } = \color{#FF6800}{ \dfrac { 7 \pm \sqrt{ 529 } } { 2 \times 1 } }$
$x = \dfrac { 7 \pm \sqrt{ \color{#FF6800}{ 529 } } } { 2 \times 1 }$
$ $ Organize the part that can be taken out of the radical sign inside the square root symbol $ $
$x = \dfrac { 7 \pm \color{#FF6800}{ 23 } } { 2 \times 1 }$
$x = \dfrac { 7 \pm 23 } { 2 \color{#FF6800}{ \times } \color{#FF6800}{ 1 } }$
$ $ Multiplying any number by 1 does not change the value $ $
$x = \dfrac { 7 \pm 23 } { \color{#FF6800}{ 2 } }$
$\color{#FF6800}{ x } = \color{#FF6800}{ \dfrac { 7 \pm 23 } { 2 } }$
$ $ Separate the answer $ $
$\begin{array} {l} \color{#FF6800}{ x } = \color{#FF6800}{ \dfrac { 7 + 23 } { 2 } } \\ \color{#FF6800}{ x } = \color{#FF6800}{ \dfrac { 7 - 23 } { 2 } } \end{array}$
$\begin{array} {l} x = \dfrac { \color{#FF6800}{ 7 } \color{#FF6800}{ + } \color{#FF6800}{ 23 } } { 2 } \\ x = \dfrac { 7 - 23 } { 2 } \end{array}$
$ $ Add $ 7 $ and $ 23$
$\begin{array} {l} x = \dfrac { \color{#FF6800}{ 30 } } { 2 } \\ x = \dfrac { 7 - 23 } { 2 } \end{array}$
$\begin{array} {l} x = \color{#FF6800}{ \dfrac { 30 } { 2 } } \\ x = \dfrac { 7 - 23 } { 2 } \end{array}$
$ $ Do the reduction of the fraction format $ $
$\begin{array} {l} x = \color{#FF6800}{ \dfrac { 15 } { 1 } } \\ x = \dfrac { 7 - 23 } { 2 } \end{array}$
$\begin{array} {l} x = \color{#FF6800}{ \dfrac { 15 } { 1 } } \\ x = \dfrac { 7 - 23 } { 2 } \end{array}$
$ $ Reduce the fraction to the lowest term $ $
$\begin{array} {l} x = \color{#FF6800}{ 15 } \\ x = \dfrac { 7 - 23 } { 2 } \end{array}$
$\begin{array} {l} x = 15 \\ x = \dfrac { \color{#FF6800}{ 7 } \color{#FF6800}{ - } \color{#FF6800}{ 23 } } { 2 } \end{array}$
$ $ Subtract $ 23 $ from $ 7$
$\begin{array} {l} x = 15 \\ x = \dfrac { \color{#FF6800}{ - } \color{#FF6800}{ 16 } } { 2 } \end{array}$
$\begin{array} {l} x = 15 \\ x = \color{#FF6800}{ \dfrac { - 16 } { 2 } } \end{array}$
$ $ Do the reduction of the fraction format $ $
$\begin{array} {l} x = 15 \\ x = \color{#FF6800}{ \dfrac { - 8 } { 1 } } \end{array}$
$\begin{array} {l} x = 15 \\ x = \dfrac { - 8 } { \color{#FF6800}{ 1 } } \end{array}$
$ $ If the denominator is 1, the denominator can be removed $ $
$\begin{array} {l} x = 15 \\ x = \color{#FF6800}{ - } \color{#FF6800}{ 8 } \end{array}$