54:(21-15);8-(62:7)-134-128

Let's solve the expressions one step at a time.

1. Start with the first expression: 54:(21-15)

   • Calculate the value inside the parentheses: \(21 - 15 = 6\)
   • Now divide \(54\) by \(6\): \[ 54 \div 6 = 9 \]

   So, 54:(21-15) = 9.

2. Next, solve the second expression: 8-(62:7)-134-128

   • First, calculate \(62:7\) (which is \(62 \div 7\)): \[ 62 \div 7 \approx 8.8571 \]
   • Replace \(62:7\) in the expression: \[ 8 - 8.8571 - 134 - 128 \]
   • Simplify the expression step-by-step: \[ 8 - 8.8571 \approx -0.8571 \] Now, include \(-134\): \[ -0.8571 - 134 \approx -134.8571 \] Finally, include \(-128\): \[ -134.8571 - 128 \approx -262.8571 \]

So, the complete calculations yield:

• The result of 54:(21-15) is 9.
• The result of 8-(62:7)-134-128 is approximately -262.8571.

Final answers:

• 54:(21-15) = 9
• 8-(62:7)-134-128 ≈ -262.8571.