Haha, sorry! Helping my little bro again, and he came across something else I didn't remember.
OK, please explain steps and how to answer questions like the following. Solving for X.
5=20/X (5 = 20 over X. I know the answer, just not how I got it, he needs to show his work)
And this one:
cx/a = b/m (CX over A = B over M).
Also, do any of you know a good website that he/I can look at for help when we need it? Thanks a lot, guys!!!
2006-10-29 17:54:51 · 4 answers · asked by darker_pegasus 2 in Science & Mathematics ➔ Mathematics
rewrite 5=20/x to 5/1=20/x
you have to cross multiply (numerator * denominator = numerator * denominator)
5*x = 20*1
5x=20
divide both sides by 5 and you get
5x/5 = 20/5
(5x divided by 5 is just x, the 5s cancel each other)
x=4
you do the same for the second equation(im assuming we're solving for x)
when you cross multiply you get
cx*m = a*b or
cxm = ab
divide both sides by cm to get "x" by itself
x= ab / cm
2006-10-29 18:05:46 · answer #1 · answered by tma 6 · 0⤊ 0⤋
Cut out the small bro.
5 = 20 / x
cross multimply to get
x = 20/5 = 4.
2006-10-30 02:00:30 · answer #2 · answered by blind_chameleon 5 · 0⤊ 0⤋
well 20 over x = 20:(devided) x so x = 20 devided by 5
CX x M = A x B
2006-10-30 02:04:28 · answer #3 · answered by ?:)? 3 · 0⤊ 0⤋
1. 5=20/X
Multiply both sides by X to get rid of the denominator.
5X = 20
Then divide 20 by 5 to get X.
X = 4.
2. cx/a = b/m
Cross-multiply to get rid of both denominators.
m(cx) = ab
cxm = ab
x = ab/cm
2006-10-30 02:00:49 · answer #4 · answered by lee-wlcj 2 · 0⤊ 0⤋