Answer:
[tex]y=\text{ 230 streetlights}[/tex]Step-by-step explanation:
This situation can be represented as a linear equation since it has an initial value and a constant rate of change per week. Remember that linear equations are given as:
[tex]\begin{gathered} y=mx+b \\ \text{where,} \\ m=\text{ constant rate of change} \\ b=\text{ initial value} \end{gathered}[/tex]Then, to determine how many streetlights the city will have at the end of 31 weeks, substitute x=31 into the following equation;
[tex]\begin{gathered} y=3x+137 \\ y=3(31)+137 \\ y=\text{ 230 streetlights} \end{gathered}[/tex]