What is the structure of a well-written essay?

Traditionally, it has been taught that a formal essay consists of three parts: the introductory paragraph or introduction, the body paragraphs, and the concluding paragraph. An essay does not need to be this simple, but it is a good starting point.

An instrument store gives a 10% discount to all students off the original cost of an instrument. During a back to school sale an additional 15% is taken off the discounted price. Julie, a student at the local high school, purchases a flute for $306. How much did it originally cost?

The equation, x-0.10x-0.15(x-0.10x)=306, may be used to solve the problem. Solving for x gives 0.90x - 0.15x + 0.015x = 306, where x = 400. Thus, the original price was $400.

What are the two main groups into which cells are classified?

Cells can be classified as eukaryotic or prokaryotic. Prokaryotic cells are those that do not have an enclosed nucleus. Eukaryotic cells are those with a nucleus enclosed by a membrane.