The temperature at the end of the day was 64 degrees. The temperature had increased twice during the day, once by 8 degrees and another time by 4 degrees. Which expression shows what the temperature was at the start of the day?

Answer 1

Let's denote the temperature at the start of the day as $x$.

First, the temperature increased by 8 degrees to become $x+8$.

Then, the temperature increased by 4 degrees to become $(x+8)+4$.

After both increases, the temperature was 64 degrees, so we have the equation $(x+8)+4=64$.

Simplifying the equation gives $x+12=64$, and subtracting 12 from both sides gives $x=52$.

Therefore, the expression that represents the temperature at the start of the day is $\boxed{52}$.