Question

Use the additive inverse to find −492.89−(−871.78)

Answer 1

To find \(-492.89 - (-871.78)\), we can use the property of the additive inverse. When subtracting a negative number, it's equivalent to adding its positive counterpart.

Thus,

\[
-492.89 - (-871.78) = -492.89 + 871.78
\]

Now, we can perform the addition:

1. Add the absolute values:
\[
871.78 - 492.89
\]

2. Align the numbers for addition:
\[
\begin{array}{r}
871.78 \\
-492.89 \\
\hline
\end{array}
\]

3. Subtract the values:
- Start from the rightmost digit:
- \(8 - 9\): we need to borrow, making it 18 - 9 = 9 (we borrow 1 from 7, changing it to 6)
- \(6 - 8 = -2\), so we borrow again, making it 16 - 8 = 8 (now 6 becomes 5)
- \(5 - 2 = 3\)
- Now we have \(8 - 4 = 4\)
- Lastly, \(8 - 0 = 8\)

So,

\[
871.78 - 492.89 = 378.89
\]

Therefore,

\[
-492.89 - (-871.78) = 378.89
\]

The final result is:

\[
\boxed{378.89}
\]