Complete the square to determine the minimum or maximum value of the function defined by the expression x^2 + 4x+3

What is the missing step in this proof ?

In the polynomial below, what number should replace the question mark to produce a difference of squares? x2 + ? x - 36

The map shows the location of the airport and a warehouse in a city. though not displayed on the map, there is also a factory 112 miles due north of the warehouse.a truck traveled from the warehouse to the airport and then to the factory. what is the total number of miles the truck traveled?