For the following questions answer them individually
If the sum of all the coefficients in the expansion of $$(1 + 3x - 2x^2)$$ is 128; then the greatest coefficient in the expansion of $$(1 + x)^n$$ is
If $$A = \begin{bmatrix}2x + 3 & -4 \\x + 7 & 2 \end{bmatrix}$$ and if det A = 0, then x =
If $$\alpha, \beta$$ are the roots of the equation $$7x^2 - 8x + 6 = 0$$ then $$(\alpha^2 + \beta^2)(\alpha + \beta) =$$
The distance (in metres) between two parallel tangents drawn to a circle of area 616 sq.m. is (Take $$\pi = \frac{22}{7}$$)