f(x) = 4x - m, g(x) = mx + 11, fg(x) = 8x + n. m and n are constants. Find the value of n.

If f(x) = 4x - m, and g(x) = mx +11, then the combined functions are: fg(x) = 4(mx +11) -m, or expanded to fg(x) = 4mx + 44 - m.

We are told that this function of 'f' and 'g' can also be written as fg(x) = 8x + n. This means that 8x = 4mx, as '4m' is the only co-efficient of x in the combined 'fg(x)' function. This simplifies to 8 = 4m, then further to 2 = m.

To find the value of 'n' we need to create a different equation. n = 44 - m, as this is what is left of the combined 'fg(x)' function, once the coefficient of x has been found, so must form the 'n' part of the original 'fg(x)' function.

We can sub in 'm', which we know is 2, so n = 44 -2, which simplifies to n = 42.

Therefore, our final answer is n = 42.

Answered by Angus B. Maths tutor

4201 Views

See similar Maths GCSE tutors

Related Maths GCSE answers

All answers ▸

Show that (x+1)(x+2)(x+3) can be written as ax^3+bx^2+cx+d


A trader buys 6 watches at £25 each. He scratches one of them, so he sells that one for £11. He sells the other 5 for £38 each. Find his profit as a percentage.


What is the best way to solve simultaneous equations?


Increase £160 by 45%.


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