Definition of Substitution Method. One way to solve systems of equations is by substitution. In this method, solve an equation for one variable, then substitute that solution in the other equation, and solve.
Area code 407 is found in the US state of Florida. Primarily servicing the city of Orlando (population: 921360), area code 407 covers 5 counties of Florida.Located in the Eastern time zone, area code 407 is on the same time as New York, NY. Area code 407 was brought into effect on April 16, 1988.407 was split from the parent 305 area code.rimarily servicing the city of Orlando (population: 921360), area code 407 covers 5 counties of Florida. Located in the Eastern time zone, area code 407 is on the same time as New York, NY.
Area code 405 serves the U.S. state of Oklahoma. It covers the Oklahoma City Metropolitan Area including cities such as Oklahoma City, Edmond, El Reno, Norman, Stillwater, Shawnee, Chickasha, Tuttle, and Moore.he other three area codes serving Oklahoma are 539 and 918, which cover northeastern Oklahoma (including the city of Tulsa); and 580, which serves western and southern Oklahoma.