Question

1 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.​

Answer 1

Answer:

Then , seven years ago,

Aftab's age =x−7

His daughter's age =y−7

According to the question,

x−7=7(y−7)

x−7=7y−49

x−7y=−49+7  

x−7y=−42                    …(i)

After three years,

Aftab's age =x+3

His daughter's age =y+3

According to the question,

x+3=3(y+3)

x+3=3y+9

x−3y=9−3

x−3y=6                       …(ii)

Representing equation (i) and (ii) geometrically, we plot these equations by finding points on the lines representing these two equations

x−7y=−42⟹x=7y−42

x=7y−42 42 35 49

y  12 11 13

x−3y=6⟹x=3y+6

x=3y+6  42  36 48

y  12 10 14

From the graph we can see that two lines will intersect at a point.  

x−7y=−42    

x−3y=6  

On subtracting the two equations, we get  

4y=48

or y=12

Substituting value of y in (2),  

x−36=6

∴x=42

Step-by-step explanation: