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.
Answers
Given :-
- 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.
To Find :-
- Solve the following problem Algebraically and graphically.
Solution :-
Let consider, Aftab's daughter's present age be " x " years.
And Aftab's present age be " y " years
Now,
7 years ago,
The daughter's (past) age = ( x - 7 ) years.... (1)
The Father's (past) age = ( y - 7 ) years.... (2)
3 years after
The daughter's age (future) = ( x + 3 ) years.... (3)
The Father's age (future) = ( y + 3 ) years.... (4)
According to the question :-
In 1st case
Father's (past) age = 7 × Daughter's Age { From (1) and (2) }
➹ y - 7 = 7(x - 7 )
➹ y - 7 = 7x - 49
➹ 7x - y - 49 + 7 = 0
➹ 7x - y - 42 = 0
In 2nd case
Father's (future) age = 3 × Daughter's (future) age { from (3) and (4) }
➹ y + 3 = 3(x + 3)
➹ y + 3 = 3x + 9
➹ 3x - y + 9 - 3 = 0
➹ 3x - y + 6 = 0
Therefore,
Algebraically the two situations can be represented as follows :-
➹ 3x - y + 6 = 0 ..... (5)
➹ 7x - y - 42 = 0.....(6)
Lets make Table for equation (1)
- If x = 6 then y = 24
- If x = 12 then y = 42
Then, Table for equation (2)
- If x = 12 then y = 42
- If x = 18 then y = 84
Note :- For graphically representation, refer to the attachment.
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■ Question :-
➩ 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.
■ Given :-
➬ 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
■ What I have to do :-
➭ represent this situation algebraically and graphically.
■ SolutiOn :-
Let the present age of Aftab be x .
And present age of his daughter be y .
According to first situation ,
After seven years ago,
➧ Age of Aftab = (x - 7 )
➧ Age of his daughter = ( y - 7 )
Now,
( x - 7 ) = 7( y - 7 )
➨ x - 7 = 7y - 49
➨ x - 7y = -49 + 7
➨ x - 7y = -42 ----------------(1)
According to second situation ,
After three years ago,
➧ Age of Aftab = (x + 3 )
➧ Age of his daughter = ( y + 3 )
Now,
( x + 3 ) = 3( y + 3 )
➨ x + 3 = 3y + 9
➨ x + 3y = 9 ----------------(2)
Therefore,
The algebraic represention is
x - 7y = -42
➱ x - 3y = 6
➱ For , x - 7y = -2
Therefore, x = -2 + 7y
Imp :- The suitable table is in the attachment.
For x - 3y = 6
➱ x = 6 + 3y
Imp :- The suitable table is in the attachment.
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Note :-
See the attachment for suitable table .