HP 39gs Master Manual page 342

Example 2: Simplifying surds
2 18 − 72 + 75
Simplify the surd expression:
i. Begin by entering the expression:
2 SHIFT 18 SHIFT SHIFT 72
SHIFT 75
ii. Now simplify each surd in turn
(assuming working is desired):
ENTER
ENTER ENTER
iii. Finally, select the entire expression with SHIFT and press
to simplify:
ENTER
iv. If you want the result as a decimal, press . Pressing
NUM SHIFT
will cause the calculator to analyze the decimal and re-instate
NUM
the surd.
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