Question

Solve the following system of equations by the method of substitution:
$x+y=10$, $x-y=12$

Answer 1

Given equations are

$x+y=10$ ....(1)

and $x-y=12$ ....(2)

$\therefore x=12+y$ ....(3)

Substitute this value of $x$ in equation (1), we get

$12+y+y=10$

$\Rightarrow 2y=-2$

$\Rightarrow y=-1$

Put this value in equation $3$

Therefore, $x=12-1$

$\Rightarrow x=11$

The solution is $x=11,y=-1$.