What is the formula for calculating the break-even point in sales revenue?

Part 1
Ten Short-Answer Questions
Differentiate between variable and fixed costs. Describe the two major behavior patterns. What if a cost has characteristics of both patterns?
What is meant by the term break-even point? What is a potential benefit of calculating break-even?
Why is the concept of relevant range crucial for understanding fixed-cost behavior?
What is the formula for calculating the break-even point in sales revenue?
What formula is used to solve for the break-even point in units?
How can the break-even formula be altered to calculate the number of units that must be sold to achieve a desired level of income (target income)? Show the formula and explain.
What effect would you expect the mechanization and automation of production processes to have on the break-even point?
Why might a business wish to lower its break-even point? How would it go about lowering the break-even point?
Describe three ideas that can lower the break-even point and include a simple example with numbers.