Question

What's the solution of the following linear system? y = 4x + 1 y = 4x

Answer 1

The solution of a system of equations is the point at which the two lines intersect. Since y is already isolated, we can set the equations equal to each other by doing:
4x=4x+1
Subtract 4x from both sides
0=1
Since 0 cannot equal 1 in any case, the lines never intersect. There is no solution to the problem.