Question

rationalise the denominator of √7×√21​

Answer 1

Answer:

there is no denominator

Step-by-step explanation:

√7×√21=√147=7√3

Answer 2

Answer:

(√3 + √7) / (√27 + √63 - √28 - √48)

= (√3 + √7) / {3√3 + 3√7 - 2√7 - 4√3}

= (√7 + √3) / (√7 - √3)

= [{(√7 + √3) * (√7 + √3)} / {(√7 - √3) * (√7 + √3)}]

= {(10 + 2√21) / 4}

= {(1 / 2) * (5 + √21)}

= {(5 + √21) / 2}.