Question

If the points A(2,k), B(3,4) and C(7,9) lie on a line, then find the value of k.$\left[2Marks\right]$

Answer 1

Given, the points A(2,k),B(3,4) and C(7,9) lie on a line.
Hence, the slope of line AB must be equal to the slope of line BC.$\left[1Mark\right]$

Hence, $\frac{4-k}{3-2}$ = $\frac{9-4}{7-3}$
$\Rightarrow$ k = $\frac{11}{4}$.$\left[1Mark\right]$