Rationalising
Add (3√2+7√3) and (√2−5√3)
Divide 5√11 by 3√33
Multiply 2√15 by 7√5
Simplify (√5+√7)^2
Simplify (√4−√13)(√4+√13)
Simplify (9−√3)(9+√3)
Simplify (3√5−5√2)(4√5+3√2)
Rationalise the denominator of 8/√7
Rationalise the denominator of 1/((8 + 5√2))
Simplify (7√3)/(√10 + √3)−(2√5)/(√6 + √5)−(3√2)/(√15 + 3√2) You are here
Multiple Choice Questions - Chapter 1 Class 9 Maths
Example 16
If a and b are rational numbers and (√11 − √7)/(√11 + √7) = a – b√77, find the value of a and b
Example 17
Find the values of a and b if (7 + 3√5)/(3 + √5) – (7 − 3√5)/(3 − √5) = a+√5 b
Ex 1.4, 5 (i)
If x = 1/(2 − √3), find the value of x^3 − 2x^2 − 7x + 5
If a = 5 + 2√6 and b = 1/a, then what will be the value of a^2+b^2 ?
Example 18
Example 19 Important
Rationalising
Last updated at Dec. 16, 2024 by Teachoo
Simplify (7√3)/(√10 + √3)−(2√5)/(√6 + √5)−(3√2)/(√15 + 3√2) We solve them separately (𝟕√𝟑)/(√𝟏𝟎 + √𝟑) = (7√3)/(√10 + √3) × (√10 − √3)/(√10 − √3) = (7√3(√10 − √3))/((√10)^2− (√3)^2 ) = (7√3(√10 − √3))/7 (𝟐√𝟓)/(√𝟔 + √𝟓) = (2√5)/(√6 + √5) × (√6 − √5)/(√6 − √5) = (2√5(√6 − √5))/((√6)^2− (√5)^2 ) = (2√5(√6 − √5))/1 = 2√5(√6 − √5) = 𝟐√𝟑𝟎−𝟏𝟎 (𝟑√𝟐)/(√𝟏𝟓 + 𝟑√𝟐) = (3√2)/(√15 + 3√2) × (√15 − 3√2)/(√15 − 3√2) = (3√2(√15 − 3√2))/((√15)^2− (3√2)^2 ) = (3√2(√15 − 3√2))/(15 − 9 × 2) = (3√2(√15 − 3√2))/(−3) = −√2(√15 − 3√2) Now, (𝟕√𝟑)/(√𝟏𝟎 + √𝟑)−(𝟐√𝟓)/(√𝟔 + √𝟓)−(𝟑√𝟐)/(√𝟏𝟓 + 𝟑√𝟐) = (√30−3)−(2√30−10)−(−√30+6) = √30−3−2√30+10+√30−6 = (√30−2√30+√30)+(−3+10−6) = 𝟏