For the function f(x)= -5x+2 what is f^-1(x)

Question

anonymous · Answer

this says multiply by -5 then add 2.  your inverse will say subtract 2 then divide by -5  
$$f^{-1}(x)=\frac{x-2}{-5}$$

anonymous · Answer

a more prosaic but effective way of doing this is to write 
$$y=-5x+2$$ then switch x and y and write 
$$x=-5y+2$$ and solve for y.  that will be your inverse

anonymous · Answer

$$x=-5y+2$$
$$x-2=-5y$$
$$\frac{x-2}{-5}=y$$

anonymous · Answer

and if you think about it this is just like the elementary algebra question 
SOLVE FOR X 
$$-5x+2=12$$ to do this it is like saying "i know the output, what was the input?" and the steps are identical.  now you have a function 
$$f^{-1}(x)=\frac{x-2}{-5}$$ that does it for you

anonymous · Answer

I don't know how I forgot that. Thank You :)

anonymous · Answer

welcome!