Complete the table if x and y vary directly
Answers
Answer:
(i) X1/Y1 = 3/4.5 = 1/1.5
X2/Y2 = 5/7.5 = 1/1.5
X3/Y3 = 8/12 = 1/1.5
X4/Y4 = 11/16.5 = 1/1.5
⇒ X1/Y1 = X2/Y2 = X3/Y3 = X4/Y4
Yes, x and y vary directly
(ii) x1/y1 = 16/32 = ½
X2/y2 = 30/60 = ½
X3/y3 = 40/80 = ½
X4/y4 = 56/84 = 28/42 = 14/21 = 7/3
⇒ x1/y1 = x2/y2 = x3/y3 ≠ x4/y4
X and y are not in direct variation.
(iii) x1/y1 = 27/81 = 3/9 = 1/3
X2/y2 = 45/150 = 15/50 = 3/10
X3/y3 = 54/216 = 18/72 = ¼
X4/y4 = 75/225 = 25/45 = 5/9
⇒ x1/y1 ≠ x2/y2 ≠ x3/y3 ≠ x4/y4
X and y are not in direct variation
Answer:
(i) X1/Y1 = 3/4.5 = 1/1.5
X2/Y2 = 5/7.5 = 1/1.5
X3/Y3 = 8/12 = 1/1.5
X4/Y4 = 11/16.5 = 1/1.5
⇒ X1/Y1 = X2/Y2 = X3/Y3 = X4/Y4
Yes, x and y vary directly
(ii) x1/y1 = 16/32 = ½
X2/y2 = 30/60 = ½
X3/y3 = 40/80 = ½
X4/y4 = 56/84 = 28/42 = 14/21 = 7/3
⇒ x1/y1 = x2/y2 = x3/y3 ≠ x4/y4
X and y are not in direct variation.
(iii) x1/y1 = 27/81 = 3/9 = 1/3
X2/y2 = 45/150 = 15/50 = 3/10
X3/y3 = 54/216 = 18/72 = ¼
X4/y4 = 75/225 = 25/45 = 5/9
⇒ x1/y1 ≠ x2/y2 ≠ x3/y3 ≠ x4/y4
X and y are not in direct variation