If the points (2, 2-2x), (1, 2) and (2, b - 2x) are collinear, the value of b is -

If the points (2, 2-2x), (1, 2) and (2, b - 2x) are collinear, the value of b is - - চর্চা

Solution: (c); $\left|\begin{array}{ccc}2 & 2-2 x & 1 \\ 1 & 2 & 1 \\ 2 & b-2 x & 1\end{array}\right|=0 \Rightarrow\left|\begin{array}{ccc}1 & 1 & 1 \\ 2-2 x & 2 & b-2 x \\ 2 & 1 & 2\end{array}\right|=0$ $\Rightarrow 4-b+2 x+2 b-4 x-4+4 x+2-2 x-4=0 \Rightarrow b=2$