A liquid's temperature was first cooled by 10 degrees Celsius, then increased by 4 degrees Celsius. If the final temperature is 17 degrees Celsius, what was the initial temperature?

Step 1: Set up the equation based on the given information.
Let $T_i$ be the initial temperature of the liquid.
The liquid was first cooled by $10^\circ\text{C}$, so its temperature became $T_i - 10$.
Then, its temperature was increased by $4^\circ\text{C}$, so it became $(T_i - 10) + 4$.
The final temperature is given as $17^\circ\text{C}$.

Step 2: Formulate the equation and solve for $T_i$.

$$T_i - 10 + 4 = 17$$ $$$$