Aftab tells his daughter

Let the present ages of Aftab and his daughter be x year and y year respectively. Then the algebraic representation is
Given by the following equations:
x - 7 = 7(y - 7)
{tex}\Rightarrow{/tex} x - 7y + 42 = 0 ...(1)
And x + 3 = 3(y + 3)
{tex}\Rightarrow{/tex} x - 3y - 6 = 0 ...(2)
To, represent this equation graphically, well find two solution for each equation, These solution are given below;
For Equation (1) x - 7y + 42 = 0
{tex}\Rightarrow{/tex} 7y = x + 42
{tex}\Rightarrow y = \frac{{x + 42}}{7}{/tex}
Table 1 of solutions

For Equation (2) x - 3y - 6 = 0
{tex}\Rightarrow{/tex} 3y = x - 6
 {tex}\Rightarrow y = \frac{{x - 6}}{3}{/tex}
Table 2 of solutions

  We plot the A(0, 6) and B(7, 7)
Corresponding to the solutions in table 1 on a graph paper to get the line AB representing the equation (1) and the points C(0, -2) and D(6, 0) corresponding to the solutions in table 2 on the same graph paper to get the line CD representing the equation (2), as shown in the figure

We observe in figure that the two lines representing the two equations are intersecting at the point P(42, 12).