1. **State the problem:** Translate the sentence "43 is the difference of Jenny's height and 21" into an equation using the variable $j$ for Jenny's height. 2. **Understand the sentence:** The phrase "difference of Jenny's height and 21" means subtracting 21 from Jenny's height, which is $j - 21$. 3. **Set up the equation:** The sentence says 43 equals this difference, so we write: $$43 = j - 21$$ 4. **Explain the equation:** This means that when you subtract 21 from Jenny's height $j$, the result is 43. 5. **Optional: Solve for $j$ to find Jenny's height:** Add 21 to both sides: $$43 + 21 = j - 21 + 21$$ Simplify: $$64 = j$$ So, Jenny's height is 64. **Final equation:** $$43 = j - 21$$