3 – y = 4 …(i)
Substituting y = -1 in L.H.S. of equation (i),
L.H.S. = 3 – (- 1)
= 3 + 1
= 4
R.H.S. = 4
∴ L.H.S. = R.H.S.
∴ y = – 1 is the solution of the given equation.
Substituting y = 1 in L.H.S. of equation (i),
L.H.S. = 3 - (1)
= 2
R.H.S. = 4
∴ L.H.S. ≠ R.H.S.
∴ y = 1 is not the solution of the given equation.
Substituting y = 2 in L.H.S. of equation (i),
L.H.S. = 3 - (2)
= 1
R.H.S. = 4
∴ L.H.S. ≠ R.H.S.
∴ y = 2 is not the solution of the given equation.