If A (a, a − b), B (a + b, − b) and C (b, a) are three collinear points, where a, b, c, $\in \mathbb{R}$, then :

For what value of k, the following system of equations has infinitely many solutions?

$x + 2y = 5, 3x + ky = 15$

Match List-I with List-II

Let $A$ be any invertible square matrix. Then

Choose the correct answer from the options given below:

Let $A = [a_{ij}]$ is given by $A = \begin{bmatrix} 1 & -1 & 2 \\ 3 & 4 & -5 \\ 2 & -1 & 3 \end{bmatrix}$. Then the matrix $B = [b_{ij}]$, where $b_{ij}$ = Minor of $a_{ij}$ is:

Let A = PQ. The elementary operation on A, that produces the same effect as it does on applying on P and keeping Q unchanged is :

(A) $R_i \leftrightarrow R_j$

(B) $R_i \to R_i + KR_j$

(C) $C_i \to KC_i$

(D) $C_i \to C_i + KC_j$

Choose the correct answer from the options given below :

The value of the expression $\frac{x^2 + y^2}{x - y}$ is:

If A is a 3x3 matrix then:

Match the LIST-I with LIST-II

Choose the correct answer from the options given below: