Question

Check which of the following are solutions of the equation x – 2y = 4 and which are not:

(i) (0, 2)

(ii) (2, 0)

(iii) (4, 0)

(iv) $(\sqrt 2 , 4 \sqrt2)$

(v) (1, 1)

Answer 1

(i) (0, 2)

Putting x = 0 and y = 2 in the L.H.S of the given equation,

x − 2y = 0 − 2× − 4 ≠ 4 2

= L.H.S ≠ R.H.S

Therefore, (0, 2) is not a solution of this equation.

(ii) (2, 0)

Putting x = 2 and y = 0 in the L.H.S of the given equation,

x − 2y 2 − 2 × 0 = 2 ≠ 4

= L.H.S ≠ R.H.S

Therefore, (2, 0) is not a solution of this equation.

(iii)(4, 0)

Putting x = 4 and y = 0 in the L.H.S of the given equation,

x − 2y = 4 − 2(0)

= 4 = R.H.S

Therefore, (4, 0) is a solution of this equation.

**(iv) **$\sqrt2,4\sqrt2$

=$\sqrt2-8\sqrt2=-7\sqrt2 ≠4$

=L.H.S ≠ R.H.S

Therefore $\sqrt2,4\sqrt2$ is not a solution of this equation.

(v) (1, 1)

Putting x = 1 and y = 1 in the L.H.S of the given equation,

x − 2y 1 − 2(1) = 1 − 2 = − 1 ≠ 4

= L.H.S ≠ R.H.S

Therefore, (1, 1) is not a solution of this equation.