Question

after rationalisation of denominator of 2/3-√7 we get

Answer 1

To Find :

• We have to rationalize the denominator of 2/3 - √7

Solution :

Dor rationalising the denominator we have Multiply the numerator and denominator by the Denominator but we should change the sign.

• (-) changes into (+)
• (+) changes into (-)

›› 2/3- √7 × (3 +√7)/(3 +√7)

›› 2(3 + √7)/(3 - √7)(3 +√7)

• By using identity
• (a + b)(a - b) = a² - b²

›› 2(3 + √7)/(3² - √7²)

›› 2(3 + √7)/(9 - 7)

›› 2(3 + √7)/2

›› 3 + √7

━━━━━━━━━━━━━━━━━━━━━━━━━