Question

Solve the following pairs of equations, graphically:

$x+y=0$ and $y=5$

• A. $(5,-5)$
• B. $(-5,-5)$
• C. $(-5,5)$
• D. $(5,5)$

Answer 1

The correct option is C $(-5,5)$

The solution set of equation $x+y=0$ is as follows:

If $x=0$ then,

$0+y=0\Rightarrow y=0$

If $x=-5$ then

$-5+y=0\Rightarrow y=5$

The required points to plot are $(0,0),(-5,5)$.

Another equation of a line given is $y=5$.

Plot all the above points of the line $x+y=0$ and the line parallel to $x$ axis that is $y=5$ in the graph. Since the point of intersection in the graph is $(-5,5)$.

Hence the solution is $x=-5,y=5$.