Solution:
Given that the temperature after x minutes is represented by the equation:
[tex]\begin{gathered} y=78+20x \\ where \\ y\Rightarrow final\text{ temperarure in degree fahrenheit} \\ x\text{ }\Rightarrow time\text{ in minutes} \end{gathered}[/tex]When x=1, we have
[tex]\begin{gathered} y=78+20x \\ where \\ x=1 \\ thus, \\ y=78+20(1)=78+20 \\ \Rightarrow y=98 \end{gathered}[/tex]The y-value represents the oven's temperature after 1 minute.