Question

Solve the equations: $x-y=-5$ and $x+y=1$ using graphical method

• A. (-2, -3)
• B. (-2, 3)
• C. (3, 2)
• D. (-3, -2)

Answer 1

The correct option is B (-2, 3)

$x-y=-5$ ----- (1)
$x+y=1$ ----- (2)
From equation (1) assume the value of $x$ and $y$ to satisfy the equation to zero.
$x-y+5=0$ ------ (3)
Put $x=0,y=5$ in equation (3)
$0-5+5=0$
$0=0$
Again put $x=-2,y=3$ in equation (3)
$-2-3+5=0$
$-5+5=0$
$0=0$
Now plotting $(0,5),(-2,3)$ and joining them, we get a straight line.
From equation (2) assume the value of $x$ and $y$ to satisfy the equation to zero.
$x+y-1=0$ ----- (4)
Put $x=0,y=1$ in equation (4)
$0+1-1=0$
$0=0$
Again put $x=-2,y=3$ in equation (4)
$-2+3-1=0$
$-3+3=0$
$0=0$
Plotting $(0,1),(-2,3)$ and joining them, we get another straight line.
These lines intersect at the point $(-2,3)$ and therefore the solution of the equation is $x=-2,y=3$