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       <dc:date>2026-06-07T21:12:54+00:00</dc:date>
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        <dc:date>2025-01-21T16:13:59+00:00</dc:date>
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        <title>Question 2, Exercise 2.6</title>
        <link>https://beta.mathcity.org/math-11-nbf/sol/unit02/ex2-6-p2?rev=1737476039&amp;do=diff</link>
        <description>Question 2, Exercise 2.6

Solutions of Question 2 of Exercise 2.6 of Unit 02: Matrices and Determinants. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $\lambda$$\lambda$$2 x_{1}-\lambda x_{2}+x_{3}=0$$2 x_{1}+3 x_{2}-x_{3}=0$$3 x_{1}-2 x_{2}+4 x_{3}=0$\begin{align*}
&amp;2 x_{1}-\lambda x_{2}+x_{3}=0 \cdots(i)\\
&amp;2 x_{1}+3 x_{2}-x_{3}=0\cdots(ii)\\
&amp;3 x_{1}-2 x_{2}+4 x_{3}=0\cdots(iii)\\
\end{ali…</description>
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        <dc:date>2025-01-21T16:13:59+00:00</dc:date>
        <dc:creator>Anonymous (anonymous@undisclosed.example.com)</dc:creator>
        <title>Question 1, Exercise 2.6</title>
        <link>https://beta.mathcity.org/math-11-nbf/sol/unit02/ex2-6-p1?rev=1737476039&amp;do=diff</link>
        <description>Question 1, Exercise 2.6

Solutions of Question 1 of Exercise 2.6 of Unit 02: Matrices and Determinants. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $ 2 x_{1}-3 x_{2}+4 x_{3}=0$$x_{1}-2 x_{2}+3 x_{3}=0$$4 x_{1}+x_{2}-6 x_{3}=0$\begin{align*}
&amp;2 x_{1}-3 x_{2}+4 x_{3}=0\cdots (i)\\
&amp;x_{1}-2 x_{2}+3 x_{3}=0\cdots (ii)\\
&amp;4 x_{1}+x_{2}-6 x_{3}=0\cdots (iii)\\
\end{align*}\begin{align*}
A &amp;= \le…</description>
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        <dc:creator>Anonymous (anonymous@undisclosed.example.com)</dc:creator>
        <title>Question 3, Exercise 2.6</title>
        <link>https://beta.mathcity.org/math-11-nbf/sol/unit02/ex2-6-p3?rev=1737476039&amp;do=diff</link>
        <description>Question 3, Exercise 2.6

Solutions of Question 3 of Exercise 2.6 of Unit 02: Matrices and Determinants. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $2 x+3 y+4 z=2$$2 x+y+z=5$$3 x-2 y+z=-3$\begin{align*}
\begin{aligned}
2x + 3y + 4z &amp;= 2 \\
2x + y + z &amp;= 5 \\
3x - 2y + z &amp;= -3
\end{aligned}\end{align*}\begin{align*}
A_{b} &amp;=\quad \left[\begin{array}{cccc}
2 &amp; 3 &amp; 4 &amp; 2 \\
2 &amp; 1 &amp; 1 &amp; 5 \\
3…</description>
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        <title>Question 1, Exercise 2.2</title>
        <link>https://beta.mathcity.org/math-11-nbf/sol/unit02/ex2-2-p1?rev=1737476039&amp;do=diff</link>
        <description>Question 1, Exercise 2.2

Solutions of Question 1 of Exercise 2.2 of Unit 02: Matrices and Determinants. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $A=\left[a_{i j}\right]$$2 \times 2$$a_{i j}=\dfrac{i+3 j}{2}$\( a_{ij} = \dfrac{i + 3j}{2} \)\( i = 1, j = 1 \)\[
a_{11} = \dfrac{1 + 3 \cdot 1}{2} = \dfrac{1 + 3}{2} = \dfrac{4}{2} = 2
\]\( i = 1, j = 2 \)\[
a_{12} = \dfrac{1 + 3 \cdot 2}{2} …</description>
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        <dc:creator>Anonymous (anonymous@undisclosed.example.com)</dc:creator>
        <title>Question 13, Exercise 2.2</title>
        <link>https://beta.mathcity.org/math-11-nbf/sol/unit02/ex2-2-p13?rev=1737476039&amp;do=diff</link>
        <description>Question 13, Exercise 2.2

Solutions of Question 13 of Exercise 2.2 of Unit 02: Matrices and Determinants. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $X$$Y$$2 X-Y=\left[\begin{array}{ccc}1 &amp; 6 &amp; -3 \\ 2 &amp; 1 &amp; 7\end{array}\right]$$X+3 Y=\left[\begin{array}{ccc}4 &amp; 3 &amp; 2 \\ 1 &amp; -3 &amp; 0\end{array}\right]$\begin{align*}
2X - Y = \begin{pmatrix} 1 &amp; 6 &amp; -3 \\ 2 &amp; 1 &amp; 7 \end{pmatrix} \cdots (i)\\…</description>
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        <dc:date>2025-01-21T16:13:59+00:00</dc:date>
        <dc:creator>Anonymous (anonymous@undisclosed.example.com)</dc:creator>
        <title>Question 6, Exercise 2.6</title>
        <link>https://beta.mathcity.org/math-11-nbf/sol/unit02/ex2-6-p6?rev=1737476039&amp;do=diff</link>
        <description>Question 6, Exercise 2.6

Solutions of Question 6 of Exercise 2.6 of Unit 02: Matrices and Determinants. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $5 x+3 y+z=6$$2 x+y+3 z=19$$x+2 y+4 z=25$\begin{align*}
A &amp;= \begin{bmatrix}
5 &amp; 3 &amp; 1 \\
2 &amp; 1 &amp; 3 \\
1 &amp; 2 &amp; 4
\end{bmatrix}, \quad
X = \begin{bmatrix}
x \\
y \\
z
\end{bmatrix}, \quad
B = \begin{bmatrix}
6 \\
19 \\
25
\end{bmatrix}
\end{alig…</description>
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        <dc:creator>Anonymous (anonymous@undisclosed.example.com)</dc:creator>
        <title>Question 6, Exercise 2.3</title>
        <link>https://beta.mathcity.org/math-11-nbf/sol/unit02/ex2-3-p6?rev=1737476039&amp;do=diff</link>
        <description>Question 6, Exercise 2.3

Solutions of Question 6 of Exercise 2.3 of Unit 02: Matrices and Determinants. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $A=\left[\begin{array}{ccc}2 &amp; 1 &amp; -3 \\ 0 &amp; 1 &amp; 0 \\ 2 &amp; 1 &amp; 6\end{array}\right]$$A^{-1}$$A A^{-1}=A^{-1} A=I_{3}$\begin{align*} A &amp;= \begin{bmatrix}
2 &amp; 1 &amp; -3 \\
0 &amp; 1 &amp; 0 \\
2 &amp; 1 &amp; 6
\end{bmatrix} \end{align*}$ A^{-1} $$ A $\begin{align*}
…</description>
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        <dc:date>2025-01-21T16:13:59+00:00</dc:date>
        <dc:creator>Anonymous (anonymous@undisclosed.example.com)</dc:creator>
        <title>Question 1, Review Exercise</title>
        <link>https://beta.mathcity.org/math-11-nbf/sol/unit02/re-ex-p1?rev=1737476039&amp;do=diff</link>
        <description>Question 1, Review Exercise

Solutions of Question 1 of Review Exercise of Unit 02: Matrices and Determinants. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. $A$$m \times n$$B$$n \times p$$A B$$n \times p$$m \times p$$p \times m$$n \times n$$A$$1 \times n$$A^{t} A$$1 \times n$$n \times 1$$1 \times 1$$n \times n$$a_{i j}$$A$$a_{i j}=(-1)^{i+j} A_{i j}$$a_{i j}=(-1)^{i+j} M_{i j}$$\frac{A_{i j}}…</description>
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