Answer:
[tex]-2^{\circ}\text{F}[/tex]
Step-by-step explanation:
Let [tex]x[/tex] be the temperature on the first day
Second day temperature
[tex]x+7[/tex]
Third day temperature
[tex]x+7-10[/tex]
Fourth day temperature was [tex]1^{\circ}\text{F}[/tex]
[tex]x+7-10+6=1\\\Rightarrow x+3=1\\\Rightarrow x=1-3\\\Rightarrow x=-2^{\circ}\text{F}[/tex]
On the first day the temperature was [tex]-2^{\circ}\text{F}[/tex]
