Find the inverse of f(x)=-5x+4/7-6x

Question

suwhitney · Answer

I understand that you first make the f(x) a Y. and then you swith all of the X's and Y's, ending up with x=-5y+4/7-6y, but after that I am stuck.

anonymous · Answer

first you want to combine like terms to make it easier to find the inverse:
f(x) = -11x + 4/7
y = -11x + 4/7
write in terms of x
x = -11y+ 4/7 and solve for y:
x-4/7 = -11y
divide both sides by -11
(x-4/7)/-11 = y
x/-11 + 4/-77 = y

suwhitney · Answer

Hmm.. not sure if I understand. Because I know that the right answer is f^-1=7x-4/6x-5. Im just not sure of the exact steps taken...

anonymous · Answer

i would combine like terms first, i don't understand why you wouldn't. maybe i'm thinking about it wrong. sorry. i tried

suwhitney · Answer

It's okay.. I missplaced by scratch paper where I wrote down how he worked it out but I think it had something to do with multiplying top and bottom by the negative recripicol. (sp?) and then going from there.. thanks for trying :)