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)

RS
Answered by Robert S. Maths tutor

11747 Views

See similar Maths GCSE tutors

Related Maths GCSE answers

All answers ▸

There are 20 sweets in a bag, 5 are white and 15 are black. What is the probability that a sweet chosen at random will be white?


The point (-3, -4) is the turning point of the graph of y = x^2 + ax + b, where a and b are integers. Find the values of a and b.


Solve the simultaneous equations: x + 2y = 13, 4x - 3y = 8.


How do you solve linear algebraic equations?


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