Let's define the low temperature on Sunday as $T$ (in degrees Fahrenheit). According to the problem, the low temperature on Monday is 6°F greater than half the temperature on Sunday, and it was 5°F on Monday.

We can write the equation as:

$\frac{T}{2} + 6 = 5$

Now, solve for $T$:

1. Subtract 6 from both sides: $\frac{T}{2} = 5 - 6$ $\frac{T}{2} = -1$

2. Multiply both sides by 2 to solve for $T$: $T = -1 \times 2$ $T = -2$

So, the low temperature on Sunday was -2°F.

Would you like a more detailed explanation or have any follow-up questions? Here are some related questions:

1. How would the equation change if the temperature difference was 8°F instead of 6°F?
2. What would happen if the temperature on Monday was 0°F?
3. If the temperature on Sunday was 4°F, what would the temperature on Monday be?
4. How can this type of equation be applied in real-world temperature predictions?
5. What is the relationship between the temperatures in this problem and algebraic functions?

Tip: When dealing with temperature-related word problems, it's helpful to translate the statements into equations step-by-step, making sure to define variables clearly.