The answer is 78.
The steps:
6[5*(41-36)-(8+4)]
1. 6[5*(5)-(12)]
You do the operations between the parenthesis.
2. 6[25-12]
Follow the order of operations and in this case it's multiplying.
3. 6[13]
Finish what's left between the big parenthesis
4. =78
multiply the last number in between the parenthesis with the number outside and you'll get the answer