Solve: $\left\{ \begin{array} { l }
\frac { 1 } { x } + \frac { 1 } { y } = 3 \\
\frac { 1 } { x } - \frac { 1 } { y } = - 1
\end{array} \right.$
A) $\left( 1 , \frac { 1 } { 2 } \right)$
B) $( 1,2 )$
C) $\left( - 1 , \frac { 1 } { 2 } \right)$
D) $( - 1,2 )$

Question

Solve: $\left\{ \begin{array} { l } 
\frac { 1 } { x } + \frac { 1 } { y } = 3 \\
\frac { 1 } { x } - \frac { 1 } { y } = - 1
\end{array} \right.$
A) $\left( 1 , \frac { 1 } { 2 } \right)$
B) $( 1,2 )$
C) $\left( - 1 , \frac { 1 } { 2 } \right)$
D) $( - 1,2 )$

Quizplus · Accepted Answer

Adding the two equations gives $\frac{2}{x} = 2$, so $x = 1$. Substituting $x = 1$ into the first equation gives $\frac{1}{1} + \frac{1}{y} = 3$, so $\frac{1}{y} = 2$, which means $y = \frac{1}{2}$.

Solve {1x+1y=31x−1y=−1\left\{ \begin{array} { l } \frac { 1 } { x } + \frac { 1 } { y } = 3 \\\\\frac { 1 } { x } - \frac { 1 } { y } = - 1\end{array} \right.⎩⎨⎧​x1​+y1​=3x1​−y1​=−1​

Solve $\left\{ \begin{array} { l } \frac { 1 } { x } + \frac { 1 } { y } = 3 \\\\\frac { 1 } { x } - \frac { 1 } { y } = - 1\end{array} \right.$