Question

Solve for the value of $x$ and $y$: $x+y=15$ and $x-y=5$

Answer 1

Given: $x+y=15$ and $x-y=5$

Adding the two equations we get,

$\Rightarrow x+y+x-y=15+5$

$\Rightarrow 2x=20$

$\Rightarrow x=\frac{20}{2}=10$

Putting the value of $x$ in $x+y=15$, we get,

$\Rightarrow 10+y=15$

$\Rightarrow y=15-10=5$

Hence, $x=10$ and $y=5$.