Question
solve the following equation
Log1/3(x2+x)-log1/3(x2-x)=2
the 1/3 should be lowered and the (x^2-x) should be higher. Can someone tell me what tools to use to make them like this when posting?
x= ?
Log1/3(x2+x)-log1/3(x2-x)=2
the 1/3 should be lowered and the (x^2-x) should be higher. Can someone tell me what tools to use to make them like this when posting?
x= ?
Answers
Reiny
so the base of the log is 1/3
in general exponentiation is show with the ^ symbol
e.g. x^2 means "x squared"
subscripts are are more difficult but are usually described like you did, as long as they are well defined tutors will be able to figure it out
log<sub>1/3</sub> (x^2 + x) - log<sub>1/3</sub>(x^2 - x) = 2
log<sub>1/3</sub> [ (x^2+x)/(x^2-x)] = 2
(x^2+x)/(x^2-x) = (1/3)^2 = 1/9
cross-multiply
9x^2 + 9x = x^2 - x
8x^2 + 10x = 0
x(8x+10) = 0
x = 0 or -5/4 or -1.25
but x = 0 would make both log<sub>1/3</sub> expressions undefined
check:
if x= -1.25
we have
log<sub>1/3</sub>.3125 - log<sub>1/3</sub>2.8125
which is defined
so x = -1.25 or -5/4
in general exponentiation is show with the ^ symbol
e.g. x^2 means "x squared"
subscripts are are more difficult but are usually described like you did, as long as they are well defined tutors will be able to figure it out
log<sub>1/3</sub> (x^2 + x) - log<sub>1/3</sub>(x^2 - x) = 2
log<sub>1/3</sub> [ (x^2+x)/(x^2-x)] = 2
(x^2+x)/(x^2-x) = (1/3)^2 = 1/9
cross-multiply
9x^2 + 9x = x^2 - x
8x^2 + 10x = 0
x(8x+10) = 0
x = 0 or -5/4 or -1.25
but x = 0 would make both log<sub>1/3</sub> expressions undefined
check:
if x= -1.25
we have
log<sub>1/3</sub>.3125 - log<sub>1/3</sub>2.8125
which is defined
so x = -1.25 or -5/4