Correct the mistake from nr. 6. Thank you!

Answer:
The correct form for each case is:
Step-by-step explanation:
I'm gonna give you the reason for each case.
a) The original equation is:
Now, we're gonna solve the first part of the equation and comparate:
How you can see, the first part is different from the last number, for this reason, the mistake is the 6, then I change it by the 24.
b) The original equation is:
As the previous exercise, we're gonna solve the first part:
You must know that when you multiply two negative signs, the result is positive.
c) The original equation is:
But, this equation can be made in this form:
How you can see, the first part can't be operated or anything, the one form to operate this is removing the plus sign and operating like a multiply.