Question

here is the question:
log5(x-4)= log7x solve for x.

These are just base 10 logs.
log100 = 2
This equation has the same format as log 40 = log (2x20)

Since both sides have log base 10, you divide by log base 10 and end up with 5(x-4) = 7x, so 5x -20 =7x x=-10


One doesn't <i>exactly </i> "divide by base 10".

log5(x-4)= log7x solve for x.
take each side as exponents to the base 10, or
10^(log5(x-4))= 10^(log7x)
then
5(x-4) = 7x
and x= 10
check...
log (5(-14)= log -70
log (-70)=log(-70) and it checks

Answer 1

Did not see the answer.

Answer 2

Log5(x-4)=7x. Now remove bracket 5x-20=7x then take 5x on the other side=-20=7x-5x =-20=2x which is x=_10

Answer 3

Yes, that is correct!