Question

Hello I don't you can help me with this please

Answer 1

Approximately 10 hours

1) Gathering the data

Initial temperature: 79º F

0.8 each hour

84º

2) We can write an exponential function to find that out. So let's do it this way:

`\begin{gathered} T_f=T_0(1+0.8)^h \\ 84=79(1.8)^h \\ (84)/(79)=(79(1.8)^h)/(79) \\ 1.06=1.8^h \\ \log _(10)1.06=\log _(10)1.8^h \\ h\log _(10)1.8=\log _(10)1.06 \\ h=10.087 \end{gathered}`

Notice that since the temperature is rising, we have to add one to the factor, otherwise, it will decrease it.

Now let's convert that decimal number so that we may have a better approximation:

10 hours and 4 minutes