I'm starting with the formula m=(s-c)/s but I know what m and c are so I need to figure out what s is. But I have no idea how to do that. I've tried using real numbers eg. 0.17=(264-219)/264 but I just can't figure out how to get the number 264 when starting with 0.17 and 219... This is really doing my head in, I wish I'd paid more attention at school... Can any help explain how to get s on the left side of the equation?
m=(s-c)/s so what is s???
- Thread starter jxm
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That's the bit that's confusing me. I can see how that works if I substitute numbers in, but I don't understand it logically...? And is that one of those very specific special rules that you just have to remember, or is there some general algebra rules I'm missing that applies in this case? Basically I don't "get" where the 1 came from...
Hi jxm:
It sure is!
When starting with the expression (b)(a - 1), we multiply the number (a-1) by the number (b) using the "Distributive Property", to obtain the product ab-b.
When starting with the expression ab - b, we rewrite it as the product (b)(a-1) using a process called "factoring".
Factoring ab - b to obtain (b)(a-1) is like running the Distributive Property in reverse! ("Undistributing"?)
Google keywords 'distributive property definition examples' for additional reading.
Cheers :cool:
Thanks, I googled factoring and that kind of explained it, but it did look complicated and I was in the middle of something else - so I'll take a look tomorrow when I have a bit more time to read it properly and do some factoring examples. My current algebra skills are pretty feeble - I can usually figure it out just be using example numbers and working backwards, but things like this I guess I really need to know the rules. I was one of those kids that sat in the maths class saying "but miss, algebra is a waste of time - when are we ever going to use this in real life" - how wrong I was, I actually use it a lot. I was right about trigonometry though - total waste of time... ;-)
mmm4444bot
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ah, but you are a human animal, jxm.
Any time humans exert heavy mental effort, physical changes take place within the brain's neural networks. Pruning occurs, resulting in more efficient pathways; hundreds of thousands of new relationships are formed between encoded data -- even when those relationships concern what you believe to be unrelated topics.
The state does not force high school students to study trigonometry because the state expects citizens to prove trig identities throughout their life. It's to force you to think! Educated minds make for better citizens. (I don't know whether you've noticed, but there are a LOT of serious issues facing humanity these days that are directly related to poor reasoning skills and a lack of logical thinking.)
So, I side with Subhotosh, albeit for different reasons.
Cheers! Now, go do some more math!!
Any time humans exert heavy mental effort, physical changes take place within the brain's neural networks. Pruning occurs, resulting in more efficient pathways; hundreds of thousands of new relationships are formed between encoded data -- even when those relationships concern what you believe to be unrelated topics.
The state does not force high school students to study trigonometry because the state expects citizens to prove trig identities throughout their life. It's to force you to think! Educated minds make for better citizens. (I don't know whether you've noticed, but there are a LOT of serious issues facing humanity these days that are directly related to poor reasoning skills and a lack of logical thinking.)
So, I side with Subhotosh, albeit for different reasons.
Cheers! Now, go do some more math!!
What choice do I use to further isolate "s"?
When doing this type of problem, ask yourself the following question at each step: "what do I do to further isolate "s"-add, subtract, multiply, divide, or factor?" These are your choices-it is as simple as that!
When doing this type of problem, ask yourself the following question at each step: "what do I do to further isolate "s"-add, subtract, multiply, divide, or factor?" These are your choices-it is as simple as that!