Question

Solve the following simultaneous equations using graphical method.
$x+y=8$
$x-y=2$

Answer 1

$x+y=8$
$\therefore y=8-x$

$x$	$1$	$2$	$3$
$y$	$7$	$6$	$5$
$(x,y)$	$(1,7)$	$(2,6)$	$(3,5)$

$x-y=2$
$\therefore y=x-2$

$x$	$1$	$2$	$3$
$y$	$-1$	$0$	$1$
$(x,y)$	$(1,-1)$	$(2,0)$	$(3,1)$

From the graph, we can clearly see that $(x,y)=(5,3)$ is the solution to the given pair of simultaneous equations.