Question

Determine the equation of the line in the given graph.

Answer 1

We may take the equation in the form of $y=ax+b$.

Observe that the straight-line passes through $(5,0)$.

This means that $y=0$ when $x=5$.

But the substitution $y=0,x=5$ in the equation gives $0=5a+b$.

Thus $b=-5a$
We also observe that the line passes through $(0,5)$; that is $y=5$, whenever $x=0$.

This gives $5=0+b$ or $b=5⟹a=-1$.

Therefore, the equation of the line is $y=-x+5$ or $x+y=5$