138k views
2 votes
Confirm that f and g are inverses by showing that f(g(x)) = x and g(f(x)) = x. f(x) = quantity x minus eight divided by quantity x plus seven and g(x) = quantity negative seven x minus eight divided by quantity x minus one.

User Sebnukem
by
7.9k points

2 Answers

1 vote

Answer:

the top person is correct

Explanation:

User Axel Ros
by
8.2k points
3 votes

Answer:


g(f(x))=(-7((x-8)/(x+7))-8)/(((x-8)/(x+7))-1)\\\\g(f(x))=x


f(g(x))=(((-7x-8)/(x-1))-8)/(((-7x-8)/(x-1))+7)\\\\\\f(g(x))=x

Explanation:

First we write the function f(x)


f(x) = (x-8)/(x+7)

Now we write the function g(x)


g(x)=(-7x-8)/(x-1)

First we find
f (g (x))

To find
f(g(x)) you must enter the function g(x) into the function f(x) by making
x = g (x)


f(g(x))=(((-7x-8)/(x-1))-8)/(((-7x-8)/(x-1))+7)

Now we simplify the expression


f(g(x))=(((-7x-8)/(x-1))-8)/(((-7x-8)/(x-1))+7)\\\\\\f(g(x))=(((-7x-8-8(x-1))/(x-1)))/(((-7x-8+7(x-1))/(x-1)))\\\\\\f(g(x))=(-7x-8-8(x-1))/(-7x-8+7(x-1))\\\\\\f(g(x))=(-7x-8-8x+8)/(-7x-8+7x-7)\\\\\\f(g(x))=(-15x)/(-15)\\\\\\f(g(x))=x

Now we find
g(f(x)) doing
x = f (x)


g(f(x))=(-7((x-8)/(x+7))-8)/(((x-8)/(x+7))-1)

Now we simplify the expression


g(f(x))=(-7((x-8)/(x+7))-8)/(((x-8)/(x+7))-1)\\\\\\\g(f(x))=(((-7x+56)/(x+7))-8)/(((x-8-(x+7))/(x+7)))\\\\\\g(f(x))=(((-7x+56-8(x+7))/(x+7)))/(((x-8-(x+7))/(x+7)))\\\\\\g(f(x))=(-7x+56-8(x+7))/(x-8-(x+7))\\\\g(f(x))=(-7x+56-8x-56)/(x-8-x-7)\\\\g(f(x))=(-15x)/(-15)\\\\g(f(x))=x

User KillerKode
by
7.2k points