In this case I would immediately rewrite n² - 2n - 5 = 10 as
n² - 2n = 10 + 5 = 15.
To complete the square: Identify the coefficient of n (it is -2). Halve that, obtaining -1, square this result, and then add the outcome (1) to and subtract the outcome (1) to n² - 2n:
n² - 2n <em>+ 1 - 1 </em> = 15
Next, rewrite n² - 2n + 1 as the square of a binomial:
Answer:The base of the ladder should be placed so that it is one foot away from the building for every four feet of hight to where the ladder rests against the building. This is known as the 4 to 1 rule.
