The temperature of the given environment starts at 60ºF and decreases at a constant rate of 3ºF/h. We can write a linear equation for the room temperature as
![T=-3H+60](https://img.qammunity.org/2023/formulas/mathematics/college/8xrml54mayl27ssdp5qq7vmo5b85i44wlz.png)
Where H is the number of hours that passed. We want to know when the temperature will be below 32ºF, in another words
![T<32](https://img.qammunity.org/2023/formulas/mathematics/college/naxm582fwti495333f4x8wmddlry7ovp9q.png)
If we substitute the expression for the temperature on the inequality, we're going to have
![-3H+60<32](https://img.qammunity.org/2023/formulas/mathematics/college/fdmd1u0gm4nn8lif19ucotk7b4uwonvn69.png)
Solving for H:
![\begin{gathered} -3H+60<32 \\ -3H<32-60 \\ -3H<-28 \\ 3H>28 \\ H>(28)/(3) \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/cql82iu8o40h0if8222lpbs99z0a4glovb.png)