466-8558+79:644-(777+888)÷4

Let's break down the expression step by step:

The expression is: \( 466 - 8558 + \frac{79}{644} - \frac{(777 + 888)}{4} \).

1. Calculate \( 777 + 888 \): \[ 777 + 888 = 1665 \]

2. Now find \( \frac{1665}{4} \): \[ \frac{1665}{4} = 416.25 \]

3. Next, look at \( \frac{79}{644} \): \[ \frac{79}{644} \approx 0.122 \]

4. Now substitute these values back into the expression: \[ 466 - 8558 + 0.122 - 416.25 \]

5. Calculate \( 466 - 8558 \): \[ 466 - 8558 = -8092 \]

6. Now, add \( 0.122 \): \[ -8092 + 0.122 \approx -8091.878 \]

7. Finally, subtract \( 416.25 \): \[ -8091.878 - 416.25 \approx -8508.128 \]

Therefore, the final result of the expression \( 466 - 8558 + \frac{79}{644} - \frac{(777 + 888)}{4} \) is approximately \( -8508.128 \).