Question

Solve the equations graphically .

$x+y=10$
$y=x+4$

Answer 1

$x+y=10$

$x+x+4=10$ since $y=x+4$

$2x=10-4=6$

$x=\frac{6}{2}=3$

Put $x=3$ in $y=x+4$ we get $y=3+4=7$

$\therefore (3,7)$ is the point of intersection of the lines $x+y=4$ and $y=x+4$ as shown in the graph.