List of top Mathematics Questions on Collinearity of points asked in AP POLYCET

If the points (1, 2), (-1, k) and (2, 3) are collinear, then the value of k is
If the points \((a,0),(0,b)\) and \((1,1)\) are collinear, then \(\frac{1}{a}+\frac{1}{b} =\)
If the points (x, 9), (0, 1) and (-6,-7) are collinear, then the value of x is