What value will replace the question mark in the following equation? $x - 1936248 = 1635773$

### Concept & Formula This is a fundamental linear equation in one variable. To isolate the unknown variable $x$, you transpose the known constant to the opposite side of the equation, which inverts its mathematical sign (subtraction becomes addition). ### Step-by-Step Solution * **Given:** $x - 1936248 = 1635773$ * **Calculation:** Transpose the negative term to the right side of the equation to isolate $x$: $$ x = 1635773 + 1936248 $$ * Add the two values: $$ x = 3572021 $$ ### Exam Strategy & Shortcut To quickly verify or eliminate options without doing the full addition, check the last two digits. The last two digits of the addends are $73$ and $48$. $73 + 48 = 121$. The correct answer must end in **21**. If multiple options end in 21, check the first few digits: $16 + 19 = 35$. The answer is roughly 3.5 million. ### Common Pitfall A frequent mistake under time pressure is subtracting the numbers instead of adding them when moving the negative value across the equals sign, incorrectly leading to $1936248 - 1635773$. ### Final Answer Therefore, the correct answer is **3572021**.