Rearranging formulae

Rearrange 1/u + 1/v = 1/f

to make u the subject of the formula. Give your answer in its simplest form.

There are a number of ways to approach this problem.

By subtracting 1/v on both sides we get 1/u as the subject of the equation:

1/u = 1/f - 1/v

The inverse of the equation can be found to make the subject u:

u = 1/(1/f - 1/v)

This can be simplified by multiplying by fv/fv:

u(fv/fv) = fv/(fv/f - fv/v)

As fv/fv is equal to one, this can be simplified further to give the final answer:

u = fv/(v-f)

Answered by Robert S. Maths tutor

10819 Views

See similar Maths GCSE tutors

Related Maths GCSE answers

All answers ▸

Find x and y of these two equations: 2x - 3y = 13 and 3x + y = 3


A rectangle has the side lengths root6m and root3m, what is the area of the rectangle in its simplest form.


what is the gradient and y intercept of the equation y=7x+7


A lorry can travel 35 miles per litre of diesel that costs £7.30 per litre. What is the cost in £ (to the nearest 2 decimal places) of the diesel used in driving the lorry 200 miles?


We're here to help

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

© MyTutorWeb Ltd 2013–2025

Terms & Conditions|Privacy Policy
Cookie Preferences