Math homework, need a lil hand not asking for you to do it for me

[kinkywink]

one question i had is log(2x+3) = 2 + log(5x-3)

 

i got this down to log(2x+3)/(5x-2) = 2

 

which then lead to 10^log(2x+3)/(5x-2) = 10^2

 

which simplifies to (2x+3)/(5x-2) = 100

 

my problem now is ive completely forgotten how to divide brackets.. i actually dont think ive been taught it at all..

[mrogicom]

try looking on Wolfram Alfa, but i think you just have to divide the numbers in the brackets with eachother?

[kinkywink]

try looking on Wolfram Alfa, but i think you just have to divide the numbers in the brackets with eachother?

ill check it out, i know x is = to 0.48888 according to my calc but i need the working

[LukaP]

You do it exactly the same as if you multiplied, just that you divide the numbers

So rhis it

2x/5x - 2x/2 + 3/5x - 3/2 = 100

[kinkywink]

You do it exactly the same as if you multiplied, just that you divide the numbers

So rhis it

2x/5x - 2x/2 + 3/5x - 3/2 = 100

ooh perfect thanks

[LukaP]

ooh perfect thanks

Anytime, now just put numbers on one side and x's on the other and solve for x.

Also if this is maths and not physics/engineering homework, dont approximate x. Say that x is eg. 5sqrt(34) instead of x.yzuv

[TideRower]

To solve (2x+3)/(5x-3) = 100 just multiply with (5x-3)

2x+3=500x-300 

x=101/166

 

The method mentioned above doesn't work. You can't divide those polynoms with each other because their degree is the same.