The answer is 8x.
You are combining like terms as 5 and 3 both have x so you are simply adding 5+3= 8
Answer: This is a type of Synthesis reaction.
Explanation:
- Synthesis reaction is a type of chemical reaction in which two or more substances combine to form a single substance.

- Decomposition reactions are a type of chemical reactions in which a substance breaks down into two or more substances.

- Combustion reaction is a type of chemical reaction in which a hydrocarbon reacts with oxygen gas to produce carbon dioxide and water.

For the given reaction:

Here, 2 substances are combining together to form a single substance. Hence, it is considered as a synthesis reaction.
-7 to make 4 so -4x=4 x=-1
The answer is x=-1
Hope this helps:)