✓ 1 MARKS
MCQ
🔥 APPEARED IN 3 BOARD SETS
If $\begin{vmatrix} -1 & -2 & 5 \\ -2 & a & -1 \\ 0 & 4 & 2a \end{vmatrix} = -86$, then the sum of all possible values of $a$ is
A
4
B
5
C
$-4$
D
9
01 // VERIFIED BOARD OCCURRENCES
| Year | Paper Code | Set | Position |
|---|---|---|---|
| CBSE 2026 | Series 65-2 | Set 1 | Question 6 |
| CBSE 2026 | Series 65-2 | Set 2 | Question 17 |
| CBSE 2026 | Series 65-2 | Set 3 | Question 10 |
02 // OFFICIAL CBSE MARKING SCHEME BREAKDOWN
- Step 1: Stating the fundamental formula / law statement (+1 Mark)
- Step 2: Intermediate mathematical substitution or proof steps (+1 Mark)
- Step 3: Correct final value or conclusion with mandatory SI units (+1 Mark)