Question

If f(x) = 4x + 21 and g(x) = 2x + 2 what is f[g(7)]

Answer 1

Answer:

we conclude:

 $f(g(7)) =85$

Step-by-step explanation:

Given

$f(x) = 4x + 21$

$g(x) = 2x + 2$

To determine

$f(g(7)) =?$

In order to determine f(g(7)), the first step we need to do is to determine g(7)

so substitute x = 7 in g(x) = 2x + 2

$g(x) = 2x + 2$

$g(7) = 2(7) + 2$

$g(7) = 14 + 2$

$g(7) = 16$

so now we have

$f(g(7)) =f(16)$

The next step to do is to substitute x = 16 in f(x) = 4x + 21

$f(x) = 4x + 21$

$f(16) = 4(16) + 21$

$f(16) = 64 + 21$

$f(16) = 85$

so we have

$f(g(7)) =f(16)=85$

Therefore, we conclude:

 $f(g(7)) =85$

Answer 2

F(x) = 4x + 21
g(x) = 2x + 2


g(7) = 2(7) + 2
= 14 + 2
= 16


f [ g(7) ]

= f(16)

= 4(16) + 21

= 64 + 21

= 85

Hope it helps!