Advertisements
Advertisements
प्रश्न
Simplify the following expressions:
`(5 + sqrt7)(5 - sqrt7)`
Advertisements
उत्तर
We know that `(a + b)(a - b) = a^2 - b^2`We will use this property to simplify the expression
`(5 + sqrt7)(5 - sqrt7)`
`:. (5 + sqrt7)(5 - sqrt7) = 5^2 - (sqrt7)^2`
`= 5 xx 5 - sqrt7 xx sqrt7`
`25 - sqrt(7 xx 7)`
`= 25 - (7^2)^(1/2)`
`= 25 - 7^1`
= 18
Hence the value of expression is 18.
APPEARS IN
संबंधित प्रश्न
Express the following with rational denominator:
`16/(sqrt41 - 5)`
Express the following with rational denominator:
`30/(5sqrt3 - 3sqrt5)`
In the following determine rational numbers a and b:
`(4 + 3sqrt5)/(4 - 3sqrt5) = a + bsqrt5`
\[\sqrt[5]{6} \times \sqrt[5]{6}\] is equal to
Simplify the following expression:
`(sqrt5+sqrt2)^2`
Rationalise the denominator of the following:
`1/(sqrt7-2)`
Rationalise the denominator of the following:
`1/(sqrt5+sqrt2)`
Rationalise the denominator of the following:
`2/(3sqrt(3)`
Find the value of a and b in the following:
`(sqrt(2) + sqrt(3))/(3sqrt(2) - 2sqrt(3)) = 2 - bsqrt(6)`
Rationalise the denominator in the following and hence evaluate by taking `sqrt(2) = 1.414, sqrt(3) = 1.732` and `sqrt(5) = 2.236`, upto three places of decimal.
`4/sqrt(3)`
