functions problem

Question

f(x)=g(x)−1, g(x)=5x+2. Find f(4)−g(2)

Answer 1

I would first find  f(x).  Then find the difference between the two functions using their respective x values.

 

f(x) = g(x) - 1

 

f(x) = (5x + 2) - 1

 

f(x) = 5x + 1

 

 

f(x) = 5x + 1

g(x) = 5x + 2

 

 

Now you can find     f(4) - g(2)

Answer 2

Hi Kiranpreet,

 

f(4) = g(4) -1

 

g(4) = (5)(4) + 2 = 22

 

So f(4) = 22 -1 = 21

 

Now solve for g(2)--> g(2) = (5)(2)+2 = 10+2 =12.

 

Now subtract--> f(4) - g(2) = 21 - 12 = 9

 

Dan