MHT CET202617 April 2026Evening ShiftMathematicsMatricesActual
If A = bmatrix 3 & 0 & 0 0 & -5 & 0 0 & 0 & 7 bmatrix ; B = bmatrix -1 & 0 & 0 0 & 2 & 0 0 & 0 & 4 bmatrix then, (2A + 3B)⁻¹ = _______
Options
- Abmatrix 1 3 & 0 & 0 0 & - 1 4 & 0 0 & 0 & 1 26 bmatrix
- Bbmatrix 1 3 & 0 & 0 0 & 1 4 & 0 0 & 0 & 1 26 bmatrix
- Cbmatrix 1 3 & 0 & 0 0 & 1 4 & 0 0 & 0 & - 1 26 bmatrix
- Dbmatrix - 1 3 & 0 & 0 0 & 1 4 & 0 0 & 0 & - 1 26 bmatrix
Correct answer
A. bmatrix 1 3 & 0 & 0 0 & - 1 4 & 0 0 & 0 & 1 26 bmatrix
Step-by-step solution
A = bmatrix 3 & 0 & 0 0 & -5 & 0 0 & 0 & 7 bmatrix B = bmatrix -1 & 0 & 0 0 & 2 & 0 0 & 0 & 4 bmatrix 2A = bmatrix 6 & 0 & 0 0 & -10 & 0 0 & 0 & 14 bmatrix 3B = bmatrix -3 & 0 & 0 0 & 6 & 0 0 & 0 & 12 bmatrix 2A + 3B = bmatrix 6 - 3 & 0 & 0 0 & -10 + 6 & 0 0 & 0 & 14 + 12 bmatrix = bmatrix 3 & 0 & 0 0 & -4 & 0 0 & 0 & 26 bmatrix The inverse of a diagonal matrix is obtained by taking the reciprocal of its diagonal elements. (2A + 3B)⁻¹ = bmatrix 1 3 & 0 & 0 0 & - 1 4 & 0 0 & 0 & 1 26 bmatrix Answer: bmatrix 1 3 & 0