A way to solve a linear system algebraically is to use the substitution method. The substitution method functions by substituting the one y-value with the other. We're going to explain this by using an example. We can substitute y in the second equation with the first equation since y = y.
Area code 970 is an area code serving most of the western and northern parts of Colorado.It covers Aspen, Vail, Durango, Grand Junction, Fort Collins, and Estes Park.rea code 970 is an area code serving most of the western and northern parts of Colorado.
The 977 area code is NOT a valid area code. This area code is NOT officially assigned to a known Numbering Plan Area (NPA). The 977 area code is not assigned to a city/state location. In most cases with invalid area codes like 977, tend to be used by phone numbers from telemarketing companies.