2= 2y - x
23 = 5y - 4x
isolate the x in the first equation
x = 2y - 2
now use this to substitute x in the second equation
23 = 5y - 4 (2y - 2)
23 = 5y - 8y + 6
23 = -3y + 6
-3y = 17
y = -5 2/3 (5.6 repeating )
now use that to find x in either equation.
2 = 2 (-5.66666) - x
2= -11.3 repeating - x
13.3 repeating = -x
x = -13.3 repeating
optional ** use the second equation to check