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Home » 1. Ankur tells his niece, “Seven years ago, I was seven times of your age as you were then. After three years, I will be three times of your age from now.” Represent given condition algebraically and graphically.
1. Ankur tells his niece, “Seven years ago, I was seven times of your age as you were then. After three years, I will be three times of your age from now.” Represent given condition algebraically and graphically.
CBSE | Class 10 | Exercise 3.1 | Maths | Pair of Linear Equations In Two Variables | RD Sharma
1. Ankur tells his niece, “Seven years ago, I was seven times of your age as you were then. After three years, I will be three times of your age from now.” Represent given condition algebraically and graphically.

Let the present age of Ankur and his niece be x and y respectively.

Seven years ago,

Age of Ankur =x-7 and

Age of his niece =y-7

According to question,

x-7=7(y-7)

⇒ x-7y=-42   ……… (i)

After three years from the present age, we get

x+3=3(y+3)

⇒ x-3y=6………..(ii)

Represnt equations (i) and (ii) algebraically.

To represent these equations graphically we need at least two solutions for each (i) and (ii).

And let’s put them in a table for each:

From equation (i),

x -7 0 7
y=(x+42)/7 5 6 7
x 6 3 0
y=(x-6)/3 0 -1 -2

From equation (ii),

Equation (i) and (ii) can be plotted in a graph as below:

i

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