I think this is the Transitive postulate of equality.
Personally I can't see much point in giving labels to these equalities.
Answer: 3(x+4)=x+18
Step-by-step explanation: Break down the problem. It says three times the sum of a number and 4. You have to add the number and 4 first. Since you're multiplying by 3, put the sum of a number and 4 in parentheses. This equals the same as eighteen more than the number. It set up how it sounds. Add 18 to the number.
43 total movies the type of movies is added in to confuse you pay no ttention just add the total. he keeps 8 of them
43 - 8 = 35
he gives them to 5 friends
35 DIVIDED by 5 = 7
each friend would get 7 each
Answer:
The result is 19
Step-by-step explanation:

Step 1: Parenthesizing (5-2)=3

Step 2: Exponentiation 

Step 3: Multiplication and division 3x4=12 and 6/3=2

Step 4: Addition and subtraction 9+12=21, and 21-2=19
21-2
19
The operations are ordered from highest to lowest in the order:
1. Parenthesizing,
2. Factorial,
3. Exponentiation,
4. Multiplication and division,
5. Addition and subtraction.
Hope this helps!