Question

Let f(x)=4x+7 and g(x)=3x-5. find (fog)(-4) A. -9 B. -61 C. -32 D. -17

Answer 1

Answer:

B . (fog)(-4)  = - 61

Step-by-step explanation:

Here, given  f(x) = 4 x + 7, g(x) = 3 x- 5

Now, by the COMPOSITE FUNCTION:

(f o g) (x)  = f (g(x))

Now here: )f o g) ( -4)  = f (g(-4))

Simplifying for g(x) =  3 x  - 5

 g(-4)  = 3 (-4) -  5 = -12 - 5  = -17

or, g (-4)  = -17

Now, for f(x) = 4 x + 7

f ( g(-4))  = f ( -17) = 4 (-17) + 7

= - 68 + 7 =  - 61

or, f ( g(-4))  = - 61

Hence, (fog)(-4)  = - 61