how to solve this

Question

y=4

y-2x-4

solve by substitution

Answer 1

The 2nd line is not an equation. It may be y = 2x - 4, in which you could substitute 4 for y and get 2x = 8, and x = 4.

Or maybe y - 2x = 4, in which case 4 - 2x = 4, and x = 0.

y is given as 4. Maybe this wasn't transcribed properly.