Question

can some one help me solve the equation Let f(x) = x - 2 and g(x) = x2 - 7x - 9. Find f(g(-1)).

Answer 1

First find g(-1)
g(-1)=1+7-9=-1
then it became to find f(-1)
-1-2=-3

Answer 2

I did the math. @kagıtucak is correct. It is -3.

Answer 3

can you show me how to do it

Answer 4

Sure, just a second.

Answer 5

f(x)=x-2
g(x)=x^(2)-7x-9
f(g(-1))

Setup the composite result function. fo+g notation is interpreted as f(g(x)).

Evaluate f(g(x)) by substituting in the value of g into f.
f(x^(2)-7x-9)=x^(2)-7x-9-2

Subtract 2 from -9 to get -11.
f(x^(2)-7x-9)=x^(2)-7x-11

Evaluate the result function by replacing x with -1 in the function.
(-1)^(2)-7(-1)-11

Squaring an expression is the same as multiplying the expression by itself 2 times.
((-1)(-1))-7(-1)-11

Multiply -1 by -1 to get 1.
(1)-7(-1)-11

Multiply -7 by the -1 inside the parentheses.
(1)+7*1-11

Multiply 7 by 1 to get 7.
1+7-11

Add 7 to 1 to get 8.
8-11

Subtract 11 from 8 to get -3.
-3


Hope that will help you step by step.

Answer 6

thank @Blank 

Answer 7

ǝɯoɔlǝʍ ǝɹ,noʎ :)