23+56 -86 :40 =

Let's solve the expression step by step:

1. Start with the addition:
   \( 23 + 56 = 79 \)

2. Then, subtract 86:
   \( 79 - 86 = -7 \)

3. Finally, divide by 40:
   \( -7 \div 40 = -0.175 \)

So, the final answer is \( -0.175 \).