Answer: [tex]25^{\circ}[/tex]
Step-by-step explanation:
Given
The highest temperature recorded is [tex]18^{\circ}[/tex]
The lowest temperature recorded is [tex]-7^{\circ}[/tex]
The amount of change between the high and the low temperatures is
[tex]\Rightarrow 18-(-7)=18+7\\\Rightarrow 25^{\circ}[/tex]