Answer:
see explanation
Step-by-step explanation:
Sami's error is in the second line of working
2x = 6x - 4 ← correct substitution ( subtract 6x from both sides, Sami has added 6x )
- 4x = - 4 ← correct second line ( divide both sides by - 4 )
x = 1
Substitute x = 1 into either of the 2 equations and evaluate for y
Substituting into the second equation
y = 2x = 2(1) = 2
solution is (1, 2 )