Write (3 + 2√5)/(7 + 3√5) in the form a + b√5

First multiply top and bottom by conjugate of denominator, (7-3√5), and expand(3 + 2√5)(7 - 3√5)/(7 + 3√5)(7 - 3√5)(21 + 14√5 - 9√5 - 30)/(49 + 3√5 - 3√5 - 45)Simplify top and botton(-9 + 5√5)/4Write in requested form-9/4 + (5/4)√5

BA
Answered by Beth A. Maths tutor

5981 Views

See similar Maths A Level tutors

Related Maths A Level answers

All answers ▸

Compute the indefinite integral of x^8 ln(3x)dx


Solve the simultaneous equations: (1) y – 2x – 4 = 0 , (2) 4x^2 + y^2 + 20x = 0


Why do we get cos(x) when we differentiate sin(x)?


Given that y=4x^3-(5/x^2) what is dy/dx in it's simplest form?


We're here to help

contact us iconContact ustelephone icon+44 (0) 203 773 6020
Facebook logoInstagram logoLinkedIn logo

MyTutor is part of the IXL family of brands:

© 2026 by IXL Learning