Given the function f (x) = 7x + 9, find the formula for the inverse, f -1

Question

johnweldon1993 · Answer

for the inverse....just switch the x's and y's

you have

y = 7x + 9
so
x = 7y + 9


and then solve for y again

anonymous · Answer

so how do i format the formula? I'm clueless as to where to begin.

johnweldon1993 · Answer

dont worry about it :)

so you have 

x = 7y + 9

to find the inverse...you want to isolate y

so add 9 to both sides....

you now have?

johnweldon1993 · Answer

subtract 9 from both sides*** sorry about that

anonymous · Answer

ok... yes. Thank you

johnweldon1993 · Answer

so now you have

x - 9 = 7y

you want y COMPLETELY by itself...so divide both sides by 7

$$y = \frac{ x-9 }{ 7 }$$

this would be your inverse equation :)

anonymous · Answer

OMG....makes sense...Thank you.

johnweldon1993 · Answer

lol I love it when that happens haha.....you're very welcome :)