When you solve a system of equations by the substitution method, how do you determine whether the system of equations is inconsistent?

1 answer

The solution to a system of linear Eqs is the point where they intesect. If the lines are parallel, they cannot
intersect and, therefore, have no solution.

If we solve the Eqs of two parallel lines, the answer will not make sense.
For example, we could get -15 = 30 which is not true and doesn't make
sense.

We could easily calculate and compare the slopes before solving the Eqs.
If the slopes are equal, the lines are parallel and have no solution(inconsistent).