Question

if √7+3/√7-3=a+b√21 then find the a and b values
please fast
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Answer 1

Answer:

Solution:

LHS = (√7-√3)/(√7+√3)

multiply numerator and denominator by (√7-√3),we get

= [(√7-√3)(√7-√3)]/[(√7+√3)(√7-√3)]

= (√7-√3)²/[(√7)²-(√3)²]

= [(√7)²+(√3)²-2(√7)(√3)]/(7-3)

= (7+3-2√21)/4

= (10-2√21)/4

= 10/4 -(2√21)/4

= 5/2 - √21/4

= a-b√21

Therefore,

a = 5/2 , b = 1/4

Explanation: