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

Answered by Reece P. Maths tutor

9091 Views

See similar Maths GCSE tutors

Related Maths GCSE answers

All answers ▸

Simplify: 5a + 2 – a + 9


Solve simultaneous equations x + y = 3 and -3x + 5y = 7


What does it mean to "complete the square"?


expand the brackets: (x+3)(x+2)


We're here to help

contact us iconContact usWhatsapp logoMessage us on Whatsapptelephone icon+44 (0) 203 773 6020
Facebook logoInstagram logoLinkedIn logo
Cookie Preferences