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

f(g(x))=2(cx+5)+c

fg(x)=2cx+10+c

2cx=6x

2c=6

c=3

10+c=d

d=13

IB
Answered by Imogen B. Maths tutor

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