Algebra: Simplifying Surds
Without evaluating square roots as decimals, simplify
–3 – √2
–1 – √2
=
+
√2
Worked Solution:
Rationalise the denominator
by multipling both numerator and denominator by
–1 + √2
:
–3 – √2
–1 – √2
=
( –3 – √2)( –1 + √2)
( –1 – √2)( –1 + √2)
=
3 – 3 √2 + √2 – √2
2
1 – √2
2
=
1 – 2 √2
–1
=
–1
+
2
√2
©
MEI Produced by Dr Ron Knott, 21 July 2004
Test reference:
AlgSurdSimp.html?ref=75235,qu=div