Please help me understand something (simple algebra related)

Hi all,

this is probably quite simple but I'm still relatively new to learning math, have decided to enroll on a course a while ago (unfortunately it's now the weekend and I can't contact my tutor til Monday!)

I'm trying to get my head around what is happening on the following expression:

p = ns - ( f + nc )

My course materials say this can also be be written as:

p = ns - f - nc

However I was under the impression any numbers outside the brackets are multiplied by the numbers within the brackets, so say for simplicitiess sake..

p = ns(f + nc)

would result in:

p = nsf + n^{2}sc

However with p = ns - f - nc, is that not the process of taking ns, deducting f from the result, and then deducting nc from that? Or is it instead the multiplication of ns * -f * -nc

Hope someone can clear this up for me!

Luke

Re: Please help me understand something (simple algebra related)

Quote:

Originally Posted by

**Luke1986** Hi all,

this is probably quite simple but I'm still relatively new to learning math, have decided to enroll on a course a while ago (unfortunately it's now the weekend and I can't contact my tutor til Monday!)

I'm trying to get my head around what is happening on the following expression:

p = ns - ( f + nc )

My course materials say this can also be be written as:

p = ns - f - nc

However I was under the impression any numbers outside the brackets are multiplied by the numbers within the brackets, so say for simplicitiess sake..

Your "impression" is wrong. Two "elements", whether numbers, or letters, or expressions, written together, **without** any operation symbol between them, like (2)(3), ab, (x+y)(u+ v), are multiplied. But if there is an operation symbol, such as "+" or "-" that operation is applied.

ns- (f+ nc) means that f+ nc is **subtracted** from ns: ns- (f+ nc)= ns- f- nc.

Quote:

p = ns(f + nc)

would result in:

p = nsf + n^{2}sc

However with p = ns - f - nc, is that not the process of taking ns, deducting f from the result, and then deducting nc from that? Or is it instead the multiplication of ns * -f * -nc

Hope someone can clear this up for me!

Luke

Re: Please help me understand something (simple algebra related)

Thanks HallsofIvy,

You know...Now I look at it, it is completely obvious and I can't believe I was confused. I think it's time for a study break, I've never come across a subject that makes me second guess myself so often!