420 - 20 = 400
420 + 5 = 425
so
400</= T </= 425
An oven's heating element turns on when the internal temperature falls to 20 degrees below the set temperature and turns off when the temperature reaches 5 degrees above the set temperature. You preheat the oven to 420 degrees before putting a cake in and baking it for an hour at 420. Write an inequality in terms of the temperature, T, that describes the temperature range of the oven while the cake is baking.
1 answer