Aftab tells his daughter, “Seven years ago, I was seven times as old as you were then. Also, three years from now, I shall be three times as old as you will be.” (Isn’t this interesting?) Represent this situation algebraically and graphically.
Let the present age of Aftab and his father be x years and y years respectively.
According to question,
7 years ago, we have
x – 7 = 7 (y - 7)
Or, x – 7 = 7y – 49
Or, x – 7y = - 42 …………… (1)
3 years from now, we have
(x + 3) = 3 (y + 3)
Or, x + 3 = 3y + 9
Or, x – 3y = 6 ……………. (2)
Graphical Representation
From equation (1), x – 7y = -42
Table value of x and y
x: |
0 |
-42 |
-35 |
y: |
6 |
0 |
1 |
From equation (2), x – 3y = 6
Table value of x and y
x: |
0 |
9 |
6 |
y: |
-2 |
1 |
0 |
Plotting the tables on the graph:
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