f(x) = 5 – x and g(x) = 3x + 7 (a) Simplify f(2x) + g(x – 1)

May look hard at first but once understood is simple.Question is asking to add two functions together.Firstly we begin by calculation f(2x) We know that f(x) = 5 – x, to find f(2x) we replace the x by 2xThis gives us f(2x) = 2 -2xNext we calculate g(x-1) this one is a little trickier but follows the same ideawe know that g(x) = 3x +7, to find g(x-1) we replace the x by (x-1)This gives us g(x-1) = 3(x-1) +7 We then expand the brackets to find g(x-1) = 3x-3 +7Therefore f(2x) + g(x-1) = 2-2x +3x-3+7= 9 + x

MB
Answered by Matthew B. Maths tutor

4647 Views

See similar Maths GCSE tutors

Related Maths GCSE answers

All answers ▸

f(x)=2x+c, g(x)=cx+5, fg(x)=6x+d; c and d are constants. Work out the value of d


Find x in the following equation: 4x + 8 -2x = 10


Solve 2x^2 - 3x - 1 = 0, using the quadratic formula. Give your answer to two decimal places.


Solve the quadratic equation x^2-6x+5=0


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:

© 2026 by IXL Learning