Answer:
The temperature on the first day was 10 °F.
Step-by-step explanation:
Let's find the temperature in every single step starting from the fourth day:
[tex]T_{4} = T_{3} - 6 F = 1 F[/tex]
[tex] T_{3} = 1 F + 6 F = 7 F [/tex]
Then, the temperature of the third day was 7 °F
On the third day:
[tex] T_{3} = T_{2} - 10 F = 7 F [/tex]
[tex] T_{2} = 7 F + 10 F = 17 F [/tex]
Hence, the temperature on the second day was 17 °F.
Now, on the second day:
[tex]T_{2} = T_{1} + 7 F = 17 F[/tex]
[tex] T_{1} = 17 F - 7 F = 10 F [/tex]
Therefore, the temperature on the first day was 10 °F.
I hope it helps you!