From the choices given below, choose the equation whose graph is given

1.	From the choices given below, choose the equation whose graph is given in Fig. (i) y = x + 2 (ii) y = x - 2 (iii) y = -x + 2 (iv) x + 2y = 6.[Hint : Clearly, (2,0) and (-1,3) satisfy the equation y = - x + 2]
Answer» The line passes through (-1, 3) and (2, 0) (i) y = x + 2 ⇒ 3 = -1 + 2 ⇒ 3 = 1 Which is not true (ii) y = x – 2 ⇒ 3 = -1 – 2 ⇒ 3 = -3 which is not true (iii) y = -x + 2 ⇒ 3 = 1 + 2 ⇒ 3 = 3 Also, for (2, 0) ⇒ 0 = -2 + 2 ⇒ 0 = 0 Thus, y = - x + 2 is the equation (iv) x + 2y = 6 ⇒ -1 + 6 = 6 ⇒ 5 = 6 Which is not true

From the choices given below, choose the equation whose graph is given in Fig. (i) y = x + 2 (ii) y = x - 2 (iii) y = -x + 2 (iv) x + 2y = 6.[Hint : Clearly, (2,0) and (-1,3) satisfy the equation y = - x + 2]

Answer»

The line passes through (-1, 3) and (2, 0)

(i) y = x + 2

⇒ 3 = -1 + 2

⇒ 3 = 1

Which is not true

(ii) y = x – 2

⇒ 3 = -1 – 2

⇒ 3 = -3 which is not true

(iii) y = -x + 2

⇒ 3 = 1 + 2

⇒ 3 = 3

Also,

for (2, 0)

⇒ 0 = -2 + 2

⇒ 0 = 0

Thus,

y = - x + 2 is the equation

(iv) x + 2y = 6

⇒ -1 + 6 = 6

⇒ 5 = 6

Which is not true