Let:
x = Distance from his house to the school
y = distance from school to the library = 360m
z = Distance from this house to the library
The distance from his house to the library is 3 times the distance from his house to the school, so:
[tex]z=3x[/tex]a. the distance from Ricardo's house to the school is given by:
[tex]\begin{gathered} x=z-y \\ x=3x-360 \\ solve_{\text{ }}for_{}x\colon \\ 3x-x=360 \\ 2x=360 \\ x=\frac{360}{2} \\ x=180m \end{gathered}[/tex]b. the distance between his house and the library is:
[tex]\begin{gathered} z=3(180) \\ z=540m \end{gathered}[/tex]