Skip to content
Question of 182

Q.If A=[12−35021−11]A = \begin{bmatrix} 1 & 2 & -3 \\ 5 & 0 & 2 \\ 1 & -1 & 1 \end{bmatrix}, B=[3−12425203]B = \begin{bmatrix} 3 & -1 & 2 \\ 4 & 2 & 5 \\ 2 & 0 & 3 \end{bmatrix}, C=[4120321−23]C = \begin{bmatrix} 4 & 1 & 2 \\ 0 & 3 & 2 \\ 1 & -2 & 3 \end{bmatrix} then compute (A+B)(A + B) and (B−C)(B - C). Also verify that A+(B−C)=(A+B)−CA + (B - C) = (A + B) - C.

Karnataka PUCKarnataka II PUC Board 2024Subjective· 5mImportance★★★★★
0% · 0/182 Questions
🔒 Locked · start free trial →

You're viewing a preview — the full solution, concept, methods & PYQ mapping are locked.

Start your 14-day free trial to unlock the full solution →

Add/subtract matrices element by element; both A+(B−C)A+(B-C) and (A+B)−C(A+B)-C equal [00−39−15211]\begin{bmatrix}0&0&-3\\9&-1&5\\2&1&1\end{bmatrix}, verifying the associativity.

Step 1 — Compute A+BA+B (add corresponding entries).

A+B=[1+32−1−3+25+40+22+51+2−1+01+3]=[41−19273−14].A+B=\begin{bmatrix}1+3&2-1&-3+2\\5+4&0+2&2+5\\1+2&-1+0&1+3\end{bmatrix}=\begin{bmatrix}4&1&-1\\9&2&7\\3&-1&4\end{bmatrix}.

Step 2 — Compute B−CB-C (subtract corresponding entries).

B−C=[3−4−1−12−24−02−35−22−10−(−2)3−3]=[−1−204−13120].B-C=\begin{bmatrix}3-4&-1-1&2-2\\4-0&2-3&5-2\\2-1&0-(-2)&3-3\end{bmatrix}=\begin{bmatrix}-1&-2&0\\4&-1&3\\1&2&0\end{bmatrix}.

Step 3 — Compute the left side A+(B−C)A+(B-C).

A+(B−C)=[1+(−1)2+(−2)−3+05+40+(−1)2+31+1−1+21+0]=[00−39−15211].A+(B-C)=\begin{bmatrix}1+(-1)&2+(-2)&-3+0\\5+4&0+(-1)&2+3\\1+1&-1+2&1+0\end{bmatrix}=\begin{bmatrix}0&0&-3\\9&-1&5\\2&1&1\end{bmatrix}.

Step 4 — Compute the right side (A+B)−C(A+B)-C.

Using A+BA+B from Step 1, …

Unlock everything free for 14 days

  • Full step-by-step solutions
  • Concept-first explanations
  • Methods, shortcuts & mistakes
  • PYQ mapping + timed mock tests

Full access for 14 days. No credit card required.