Solve the Expression: Finding the Equivalent Value of 78-9

To find an equivalent expression to $78 - 9$, we'll follow these steps:

• Step 1: Calculate the original expression $78 - 9$.
  The result of this subtraction is $69$.

• Step 2: Identify an expression that will also equal $69$ using equivalent smaller subtractions.

• Step 3: Examine $9$ and represent it as $8 + 1$. Hence, the original expression can be rewritten as $78 - 8 - 1$.
  Both: $\begin{aligned} &78 - 9 = 69 \\ &78 - 8 - 1 = 69 \end{aligned}$.

• Step 4: Compare the stepwise approach with the provided choices.

Among the options provided, $78-8-1$ is equivalent to $78-9$ as both yield the same result of $69$.

Therefore, the expression that is equivalent to $78 - 9$ is $78 - 8 - 1$.