Its the first one . you don't need a "," before and unless it is listing 3 or more things. with the second one the "," is in the wrong spot
Answer:
It is easy to identify a main idea that is directly expressed in the text. Main ideas are often found at the beginning of paragraphs. The first sentence often explains the subject being discussed in the passage. Main ideas are also found in the concluding sentences of a paragraph.
An example can be hot dogs and hot dog buns. If the price of one of them falls, it would lead to the product being cheaper which would increase sales, thus bringing the demand for the other one to be much higher.
