Solve the following pair of linear equations using a graph: $x+y=7$,$5x+2y=20$.

(A) $x+y=7$
$\therefore y=7-x$
For $x=0, y=7-0=7$
For $x=7, y=7-7=0$

$x$	$0$	$7$
$y$	$7$	$0$

$\therefore$ Plot the ordered pairs $(0, 7)$ and $(7, 0)$ of the solution set of $x+y=7$ on the graph paper and draw the line by joining them.
$5x+2y=20$
$\therefore 2y=20-5x \quad \therefore y=\frac{20-5x}{2}$
For $x=0, y=\frac{20-0}{2}=10$
For $x=4, y=\frac{20-20}{2}=0$

$x$	$0$	$4$
$y$	$10$	$0$

$\therefore$ Plot the ordered pairs $(0, 10)$ and $(4, 0)$ of the solution set of $5x+2y=20$ on the graph paper and draw the line by joining them.
The intersection point (common point) of these two lines is $(2, 5)$,which satisfies both equations.
Thus,the solution of the pair of linear equations is $(2, 5)$.