Write in descending order i ii

i We know that 162 96 ii We know that 141 63

Selina Solutions Class 9 Mathematics Solutions for Exercise 1(B) in Chapter 1 - Chapter 1- Rational and Irrational Numbers

Question 14 Exercise 1(B)

Write in descending order:

(i) 𝟐 √𝟔 𝟒 𝒂𝒏𝒅 𝟑 √𝟐 𝟒

(ii) 𝟕√𝟑 𝒂𝒏𝒅 𝟑√𝟕 $^{^4}$

$\begin{array}{l} 7 \sqrt{3}=\sqrt{7^{2} \times 3}=\sqrt{147} \\ 8 \sqrt{2}=\sqrt{8^{2} \times 2}=\sqrt{128} \end{array}$

Answer:

(i) $\begin{array}{l} 2 \sqrt[4]{6}=\sqrt[4]{2}^{4} \times 6=\sqrt[4] 96 \\ 3 \sqrt[4]{2}=\sqrt[4]{3^{4} \times 2}=\sqrt[4]{162} \end{array}$

We know that 162 > 96

$\begin{array}{l} \Rightarrow \sqrt[4]{162}>\sqrt[4]{96} \\ \Rightarrow 3 \sqrt[4]{2}>2 \sqrt[4]{6} \end{array}$

(ii) $\begin{array}{l} 7 \sqrt{3}=\sqrt{7^{2} \times 3}=\sqrt{141} \\ 3 \sqrt{7}=\sqrt{3^{2} \times 7}=\sqrt{63} \end{array}$

We know that 141 > 63

$\begin{array}{l} \Rightarrow \sqrt{141}>\sqrt{63} \\ \Rightarrow 7 \sqrt{3}>3 \sqrt{7} \end{array}$

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Exercises

Exercise 1(A)

Exercise 1(B)

Exercise 1(C)

Exercise 1(D)

Chapters

Chapter 1- Rational and Irrational Numbers

Chapter 2- Compound Interest [Without Using Formula

Chapter 3- Compound Interest [Using Formula

Chapter 4- Expansions

Chapter 5- Factorisation

Chapter 6- Simultaneous Equations

Chapter 7- Indices [exponents]

Chapter 8- Logarithms

Chapter 9- Triangles [Congruency in Triangles]

Chapter 10- Isosceles Triangle

Chapter 11- Inequalities

Chapter 12- Mid-Point and Its Converse

Chapter 13- Pythagoras Theorem

Chapter 14- Rectilinear Figures

Chapter 15- Construction of Polygons

Chapter 16- Area Theorems

Chapter 17- Circles

Chapter 18- Statistics

Chapter 19- Mean and Median

Chapter 20- Area and Perimeter of Plane Figures

Chapter 21- Solids

Chapter 22- Trigonometrical Ratios

Chapter 23- Trigonometrical Ratios of Standard Angles

Chapter 24- Solution Of Right Triangles

Chapter 25- Complementary angles

Chapter 26- Co-ordinate Geometry

Chapter 27- Graphical Solution

Chapter 28- Distance Formula