Step-by-step explanation
Let us first define the different types of reaction.
A combination reaction is one in which two reactants combine to form a single product.
![2Na+O_2\rightarrow Na_2O_2](https://img.qammunity.org/2023/formulas/chemistry/college/2b0xbdm3rpas6qkj25n980r2m74tanvqsn.png)
A decomposition reaction will be one in which a reactant breaks down into two or more products.
![2HCl\rightarrow H_2+Cl_2](https://img.qammunity.org/2023/formulas/chemistry/college/8beyqyikitihok0y07r4xzci1tbk3cr3jr.png)
A simple displacement reaction will be one in which a reagent, which is in its natural state, displaces one element bound to another. As a product, we will have the previously linked element now in its free form.
![Mg+MnCl_2\rightarrow Mn+MgCl_2](https://img.qammunity.org/2023/formulas/chemistry/college/wpfuop84q7trg3cowbze5zm2rmdlqcivf6.png)
In a double displacement reaction two linked elements move past each other and take each other's place.
![NaF+KBr\rightarrow NaBr+KF](https://img.qammunity.org/2023/formulas/chemistry/college/vfsksmzmnapt8defyala39rd5sm21vbchl.png)