OK, I have a long calculation involving logarithms for my HNC which is presenting me with no real dramas.

I got to a stage and for the life of me I cannot figure out why (1-2x) x 0.1875 transforms to 0.1875 – 0.375x

I’m assuming its a simply step but it really is doing my head in.

Ta 🙂

what’s on the other side of the = sign?

multiply out the bracket components and the factor:

(1-2x) X 0.1875 is the same as
1 X 0.1875 + -2 X x X 0.1875

which is 0.1875 – 0.375 X x

Same as 0.1875 (1 – 2x) no?

i.e. 0.1875 – 0.375x

OK full expression is (1.2x) x 0.1875 – 0.6355x = 0.1153

Which then transforms to 0.1875 – 0.375x – 0.6355x = 0.1153

@stoner has it (first) as does @rocketman

I think you’ve just over-thought it and confused yourself, from what you say you’ve done the hard part

(1-2x)x 0.1875 = (1 x 0.1875) – (2x x 0.1875)

= 0.1875 – 0.375x

0.1875 – 0.375x – 0.6355x = 0.1153

…

-1.0105x = -0.0722

x = 0.07145

Stoner, explained simply. Thanks all

I’m tackling this HNC after 16 years of doing no real maths . So sometimes find basic problem solving becomes a nightmare. I have tutors to ask but as I m doing it distance learning its actually quicker and easier to look n the net or obviously just ask the many on here. It really is appreciated 🙂

For fun you could also go to http://www.wolframalpha.com and type
‘solve (1-2x) * 0.1875 – 0.6355x= 0.1153’
into the search line.

It will give you the answer but then if you click on ‘step by step solution’ on the right it gives a fantastic breakdown.

It’s definitely the go-to search engine when you want a number (e.g. population of N.Korea) rather than just text

Thanks, that’s been pointed out to me a few times. I’ll check it out later 🙂

If you want to see what the explanation would look like for your example I’ve posted it here

You are probably best to download the picture to look at it as it is tall and thin and doesn’t seem to zoom well on t’web

Leffeboy, thanks for putting that effort in. had a good look at it and it all makes sense. Im finding the gaps in my knowledge are the simple things 🙂

I really enjoyed that; anyone recommend a book if I wanted to get back into maths for fun?, got an A at GCSE but that was 23 years ago

Ben, that’s probably the dullest part of maths ever!!! Try ‘You are a Mathematician’ for some much more wow stuff.

Leffeboy, thanks for putting that effort in. had a good look at it and it all makes sense

Just to be clear it wasn’t me that did that – that’s the output from Wolfram Alpha, it’s really rather nice. All I did was post the pic online

Ah cool, i tried to get Wolfram Alpha to display the full workings but i had to pay a monthly fee. I might see if its worth it down the line 🙂

have you been using youtube

some great videos on all kinds of maths

I really enjoyed that; anyone recommend a book if I wanted to get back into maths for fun?, got an A at GCSE but that was 23 years ago

Books are old school. Try Khan Academy: http://www.khanacademy.org

Video lectures, interactive learning, tests and achievements.
It’s ace for everything from basic arithmetic to astrophysics.

Yea, i mainly use the Khan Academy website and YouTube for picking up information. Like i said i have some pretty obvious gaps in my knowledge due to the amount of time since i left school until now, but the internet is a phenomenal tool with a lot of resources to help.

Ah cool, i tried to get Wolfram Alpha to display the full workings but i had to pay a monthly fee

You can do something like 3 sets of free workings each day. I just logged in using my facebook account and it seemed to all work.