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

5823 Views

See similar Maths A Level tutors

Related Maths A Level answers

All answers ▸

What does dy/dx represent?


A curve has equation x^2 + 2xy – 3y^2 + 16 = 0. Find the coordinates of the points on the curve where dy/dx =0


The curve C has parametric equations x=2cos(t) and y=3cos(2t). Find and expression for dy/dx in terms of t.


What is the gradient of the quadratic function y=3x²?


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