To determine which equation Tillie is solving, we need to analyze the effect of subtracting 8 from both sides.
If she subtracts 8 from both sides, then we can represent this mathematically:
- Let's take each of the given equations and imagine subtracting 8 from both sides.
For the first equation:
- \( 12 = -x - 8 \) Subtracting 8 from both sides gives: \( 12 - 8 = -x - 8 \) → \( 4 = -x \) (valid)
For the second equation:
- \( 12 - x = -8 \) Subtracting 8 from both sides gives: \( 12 - x - 8 = -8 \) → \( 4 - x = -8 \) (valid)
For the third equation:
- \( 12 = -x + 8 \) Subtracting 8 from both sides gives: \( 12 - 8 = -x + 8 \) → \( 4 = -x + 8 \) (valid)
For the fourth equation:
- \( 12 - x = 8 \) Subtracting 8 from both sides gives: \( 12 - x - 8 = 8 \) → \( 4 - x = 0 \) (valid)
Next, let’s reframe the origin statement. We need to identify an equation such that when 8 is subtracted from it, we will still have a valid, logical expression.
Looking at the equations, the most straightforward equation from which subtracting 8 leads directly to a simpler form is the fourth equation:
- From \( 12 - x = 8 \), when we subtract 8 from both sides, we successfully arrive at \( 12 - x - 8 = 0 \).
Thus, the equation Tillie is likely solving is:
12 − x = 8