f(x)=7x+6/x+5
what is the inverse

Question

f(x)=7x+6/x+5
what is the inverse

anonymous · Answer

When finding the inverse, you exchange the x's and y's. like this:
x=7y+6/y+5

anonymous · Answer

Then you solve for y.

anonymous · Answer

Is this how I do it?  x=(7y+6)/(y+5)

anonymous · Answer

Yea, but when i was learning this, i was told to solve for y, or f(x) as well.

anonymous · Answer

ok my answer I got is x=6/y,2

anonymous · Answer

How did you get that?

anonymous · Answer

but then I did f(x)=(7y+6)/(y+5) and got -5x-6/x-7

anonymous · Answer

Dont know what you did there..but i said to solve for y. Meaning everything will equal to y. But that depends, how does your teacher or proffessor like it to be in when its solved?

anonymous · Answer

did I set it up right? 7y+6/y+5

anonymous · Answer

Yes, but what is it equal to?

anonymous · Answer

i don't know what I am doin wrong

anonymous · Answer

$$x=\frac{7y+6}{y+5}$$

anonymous · Answer

you interchange the x and the y's, so wherever there is an x, switch with y and wherever there is a y, switch with x

anonymous · Answer

I thought I did that...

anonymous · Answer

ok now solve for y

anonymous · Answer

i can't fiqure it out..

anonymous · Answer

You multiply each side by (y+5) to get rid of the fraction.

anonymous · Answer

im still lost

anonymous · Answer

the other way would be

multiply by y+5

$$x(y+5)=7y+6$$

anonymous · Answer

$$xy+5x=7y+6$$

distribution property

$$xy-7y+5x=6$$

subtraction property

$$xy-7y=6-5x$$

subtraction propety

$$y=\frac{6-5x}{x-7}$$

anonymous · Answer

i just factored the last part

anonymous · Answer

pullout out a y and divided by x-7

anonymous · Answer

ignore my first answer... it dawned on me that 1/x is a reciprocal of the equation and the inverse is not the reciprocal

anonymous · Answer

NP.. Thank you for your help...