Work out the value of 81^(-1/4) (Non-Calculator)

To answer this question, we have to think about our power rules and use them to slowly simplify this complicated expression:81-1/4 = ((81)1/2)-1/2 (Because ((x)y)z = xyz - one of our 3 power rules)We know that 92 = 81 so if we do a power of 1/2 on both sides we get:9 = 811/2So: 81-1/4 = 9-1/2We can use a similar line of reasoning to get down to:81-1/4= 3-1We also know that a number raised to the power of -1 is equal to 1 divided by that number (x-1 = 1/x)So:81-1/4 = 1/3

RP
Answered by Reece P. Maths tutor

10696 Views

See similar Maths GCSE tutors

Related Maths GCSE answers

All answers ▸

Complete the square of the equation below.


How do you expand out and simply brackets, like the following: (x-3)(x+4)?


Aidan, Emily and Seth shared some sweets in the ratio 2 : 7: 4 Seth got 16 more sweets than Aidan. Work out the total number of sweets they shared.


S is a geometric sequence. a) Given that (√x - 1), 1, and (√x + 1) are the first three terms of S, find the value of x. b) Show that the 5th term of S is 7 + 5√2


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:

© 2025 by IXL Learning