We can see that we have the following equation:
[tex]-x+2y=11[/tex]
And we can see that this is a linear equation in standard form:
[tex]Ax+By=C[/tex]
And we need to graph the linear equation. To achieve that, we can proceed as follows:
1. We can find the intercepts of the linear function, and then we will have two points we can use to graph the line equation. We can find another point to graph it easier.
2. To find the x-intercept (the point where the line passes through the x-axis, and when y = 0) is as follows:
[tex]\begin{gathered} -x+2y=11\rightarrow y=0 \\ \\ -x+2(0)=11 \\ \\ -x=11\Rightarrow x=-11 \end{gathered}[/tex]
Therefore, the x-intercept is (-11, 0).
3. To find the y-intercept (the point where the line passes through the y-axis, and when x = 0) is as follows:
[tex]\begin{gathered} -x+2y=11\rightarrow x=0 \\ \\ 2y=11 \\ \\ \frac{2y}{2}=\frac{11}{2} \\ \\ y=5.5 \end{gathered}[/tex]
Therefore, the y-intercept is 5.5 (0, 5.5).
4. Since we have a decimal, and to be more precise, we can find another point. To do that, we can try with x = 5:
[tex]\begin{gathered} -x+2y=11 \\ \\ -5+2y=11 \\ \\ -5+5+2y=11+5 \\ \\ 2y=16\Rightarrow y=\frac{16}{2}=8 \\ \\ y=8 \\ \end{gathered}[/tex]
Then we have another pair to graph the function: (5, 8).
5. We can find another point, using x = -5. Then we have:
[tex]\begin{gathered} -x+2y=11 \\ \\ -(-5)+2y=11 \\ \\ 5+2y=11\Rightarrow5-5+2y=11-5 \\ \\ 2y=6 \\ \\ \frac{2y}{2}=\frac{6}{2}\Rightarrow y=3 \end{gathered}[/tex]
Therefore, another point is (-5, 3)
5. Now, with these values, we can sketch the graph of the line as follows (we will use (-5, 3) and (5, 8), and we will see that the line passes through the point (0, 5.5):
• (-11, 0),, (-5, 3),, (0, 5.5), ,(5, 8)
Therefore, we can see the points: (-5, 3), (0, 5.5), and (5, 8) are three points that solve the equation -x + 2y = 11, since they lie on that line:
[tex]\begin{gathered} -(-5)+2(3)=11 \\ \\ 5+6=11 \\ \\ 11=11\text{ \lparen It is true\rparen} \\ \\ \text{ And we can follow the same steps for the other two points:} \\ \\ -(0)+2(5.5)=11 \\ \\ 11=11 \\ \\ \text{ And} \\ \\ -5+2(8)=11 \\ \\ -5+16=11 \\ \\ 11=11 \end{gathered}[/tex]
Therefore, in summary, we graphed the linear function as follows, and we found that the three points on the graph solve the equation -x + 2y = 11, that is, (-5, 3), (0, 5.5), and (5, 8):
