Answer:
[tex]-19^{\circ}[/tex]
Step-by-step explanation:
Let x represent temperature on 4th day.
We have been given that the temperatures was recorded for the first three days were -2°,10°,and 7°.
The total temperature on f days would be [tex]-2^{\circ}+10^{\circ}+7^{\circ}+x[/tex].
We have been given that total temperature change was -4°. We can represent this information in an equation as:
[tex]-2^{\circ}+10^{\circ}+7^{\circ}+x=-4^{\circ}[/tex]
[tex]15^{\circ}+x=-4^{\circ}[/tex]
[tex]x=-4^{\circ}-15^{\circ}[/tex]
[tex]x=-19^{\circ}[/tex]
Therefore, the temperature on 4th day must be equal to [tex]-19^{\circ}[/tex].
