Tamilnadu Board Class 9 Maths Solutions Chapter 2 Real Numbers Ex 2.7

Tamilnadu State Board Class 9 Maths Solutions Chapter 2 Real Numbers Ex 2.7

Question 1.
Rationalise the denominator
Tamilnadu Board Class 9 Maths Solutions Chapter 2 Real Numbers Ex 2.7 1
Solution:
Tamilnadu Board Class 9 Maths Solutions Chapter 2 Real Numbers Ex 2.7 1a

Question 2.
Rationalise the denominator and simplify
Tamilnadu Board Class 9 Maths Solutions Chapter 2 Real Numbers Ex 2.7 2
Solution:
Tamilnadu Board Class 9 Maths Solutions Chapter 2 Real Numbers Ex 2.7 2a
Multiply the numerator and denominator by the rationatising factor (√27 + √18)
Tamilnadu Board Class 9 Maths Solutions Chapter 2 Real Numbers Ex 2.7 2b
Tamilnadu Board Class 9 Maths Solutions Chapter 2 Real Numbers Ex 2.7 2c

Question 3.
Find the value of a and b if \(\frac{\sqrt{7}-2}{\sqrt{7}+2}=a \sqrt{7}+b\).
Solution:
Tamilnadu Board Class 9 Maths Solutions Chapter 2 Real Numbers Ex 2.7 3

Question 4.
If x = √5 + 2 , then find the value of \(x^{2}+\frac{1}{x^{2}}\) .
Solution:
If x = √5 + 2
Tamilnadu Board Class 9 Maths Solutions Chapter 2 Real Numbers Ex 2.7 4

Question 5.
Given √2 = 1.414, find the value of \(\frac{8-5 \sqrt{2}}{3-2 \sqrt{2}}\) (to 3 places of decimals).
Solution:
Tamilnadu Board Class 9 Maths Solutions Chapter 2 Real Numbers Ex 2.7 5

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