Homework Help

Solve for x.  log (base 7) 5x-1 = log (base 7) x+7

user profile pic

kristenmarieb... | Student, Grade 10 | Valedictorian

Posted August 20, 2013 at 5:40 PM via web

dislike 1 like

Solve for x. 

log (base 7) 5x-1 = log (base 7) x+7

Tagged with algebra 2, math

1 Answer | Add Yours

user profile pic

aruv | High School Teacher | Valedictorian

Posted August 20, 2013 at 5:51 PM (Answer #1)

dislike 0 like

`log_7 (5x-1)=log_7 (x+7)`

`log_7( 5x-1)-log_7(x+7)=0`

`because`

`log_7 x-log_7 y=log_7(x/y)`

`therefore`

`log_7((5x-1)/(x+7))=0`

`log_7 1=0`

`therefore`

`(5x-1)/(x+7)=1`

`5x-1=(x+7)xx1`

`5x-x=7+1`

`4x=8`

`x=2`

Thus answer is

X=2

Join to answer this question

Join a community of thousands of dedicated teachers and students.

Join eNotes