Adance studio and a dancewear manufacturer decide to combine. this type of merger is called a

This is called a vertical merger. Vertical merger is a merger where two companies merge and operate having the same goal of providing a common product and services. This is also where the companies expand example of this is the ebay and paypal which merge to have a common service. 

you have to put the parentheses like this:

in fact, you have to perform the operation inside parentheses first, and then proceed in order: