If an equation is not true for even one point on the line, it cannot represent the relationship.

After one choice works for the first point, verify it also works for the other labeled point to be sure.

Enter the points A=(10,30) and B=(50,10).

Rewrite each equation in terms of $y$ and graph it. For example:

• $2x+y=70$ as $y=70-2x$

• $x+2y=60$ as $y=30-\frac{1}{2}x$

• $x+2y=70$ as $y=35-\frac{1}{2}x$

• $x-2y=70$ as $y=\frac{1}{2}x-35$

See which graphed line passes through both points $A$ and $B$ (both points should lie on the line). The corresponding equation is the correct choice.

From the graph, the line passes through the labeled points $(10,30)$ and $(50,10)$.

Substitute $(10,30)$ into each equation.

• $2x+y=70$: $2(10)+30=50$ (not $70$)

• $x+2y=60$: $10+2(30)=70$ (not $60$)

• $x+2y=70$: $10+2(30)=70$ (works)

• $x-2y=70$: $10-2(30)=-50$ (not $70$)

Check $(50,10)$ in $x+2y=70$: $50+2(10)=70$, so it also works.

Therefore, the equation is $x+2y=70$.