How do I solve proportions?
457981
a/b = c/d\n\nthen ad = bc\n\nso 24x = 6x9\n\nx = 54/24\n\nx = 9/4
787725
To solve a problem like that:\n\n2x-3+4x = 10 (i'm not sure if this is your answer but I'm using it as an example)\n\nFirst combine the x's on the left side to get 6x-3 = 10\n\nThen add 3 to both sides to cancel the 3 on the left side.  You will not have 6x = 10.\n\nDivide both sides by 6 to isolate the x.  You will now have x = 10/6 (or 5/3)
897845
take 35-3, which is 32.  then divide 32 by 35.  you'll get a decimal answer,  move the decimal to the right 2 spaces and that's your percent
978082
Well if you know the density of ANY two liquids and the overall weight, you ought to be abler to calculate the proportions:\n\nEG:\n\nWe have X amount of liquid with a SG of 1.2\nWe have Y amount of liquid with an SG of 1.6\nWe also know there is perhaps 3 litres and it weighs 1.4 Kg\n\n1.2 * x + 1.6 * Y = 1.4 * 3\nSimplifies\n\n12x + 16y = 14x3 (42)\n\n12x +16y = 42\n6x +8y = 21\n\nNow do basic algebra to find the proportions of the two.
572919
proportion=this\na:b=c:d\na and d=extremes\nb and c=means\nok. the means and the extremes' product has to equal the same.\nExample:\na:b=c:d\nFor more help, just buy something educational that reads "Math Success 2006" and look for Pre-Algebra.\nGo to Chapter 5\na=7\nb=11\nc=?\nd=11\nc=7 because 11x7=77\n11x7=77
584205
put 80 over 50 and set it equal to x/100\n\nx shoudl equal 160\n\ntherefore 160%
1160809
1000 ppm/1,000,000 x 100% = 0.100%\n\nIts a simple division solution.
918429
use the formulas your given\nto find the volume of the cylinder\nthen pretend the semi hemi on  the top is a sphere find the volume and multiply by 1/2\n\nadd two totals to find volume
191332
Find the dementions and multiply.
889540
I have taken the liberty of listing one or two good references as links below.  But I can give you a very brief explanation here:\n\nWe say two quanities are "in proportion" if they behave in such a way that the size of one directly affects the size of the other.  The relationship between the two quantities (let's call them 'x' and 'y') does not need to be "equal;" it could just as easily be "twice as much as" or any other ratio that you like.\n\nHow does this show up in equations?\n\nIf x and y are related by "x is twice y", we might write: x/y = 2/1.\nNotice how fractions appear on both sides of the = sign.  Most students learn to expect fractions in any "proportion problem."  Many textbooks, however, would write this equation x = 2y.\n\nContinuing with our example of x:y = 2:1 (read "x is to y as 2 is to 1"), it's fair to say that we can find one value if we know the other.  Suppose y=3.  What is the value of x?  Here's how you solve that using an equation:\n\nx/(3) = 2/1  where I've substituted '3' in place of 'y'\n\nNow, we "cross multiply" -- a handy way of simplifying a "fraction equals a fraction" equation -- and we get:\n\n1x = 3 * 2\nSo, x=6\n\nDoes that make sense?  Sure, because we expected 'x' to be twice the value of 'y' all along.  Six is twice three!\n\nSo far, I have been discussing a "direct proportion" where one quantity growing larger causes the other to grow larger.  Using the above example, if we said the value of y were 10, then x would be 20.  And so on.\n\nBut there are times when the opposite happens -- one variable shrinks in value whenever the other grows.  This is called "inversely proportional", and a typical problem goes like this:\n\nX and Y are inversely proportional.  X equals 15 when Y equals 5.  Find X when Y equals 25.\n\nFirst, we set up the inverse proportionality:\n\nX = c/Y\n\nThe only 'problem' is that we do not yet know the value of the "constant of proportionality" c.  Let's find it!\n\n15 = c/5\n\nMultiply by 5:\n\n75 = c\n\nRe-write the equation, replacing 'c' with 75:\n\nX = 75/Y\n\nThe problem I posed asks for the value of X when Y=25.\n\nSubstitute:  X = 75/(25) = 3\n\nAs predicted, X got smaller when Y grew!\n\nI hope this helps introduce you to the world of Proportions!
792123
for the first type of problem--60% of ? =45, you take 60% (which is the same as .6) and make the ? an x.  Of always means multiply, so it becomes .6x=45.  simply divide both sides by .6 and x=75. \n\nFor the second type--what % of 90 is 63, you just set it up the same way.  90X=45.  divide by 90 and you get .5 or 50%\n\nThe final type--39% of 1500, you simply multiply .39 by 1500 to get 585\n\nNow that you know how to do each type of problem, simply plug the right numbers into the equations and finish your homework.  Good luck.
438041
Since they r similar,\n\nDivide the Area of the larger cylinder by the smaller one,\n49(3.142)/25(3.142) to receive proportionality\n\n= 1.96\n\nTherefore 1.96 * volume smaller cylinder,\n\n1.96*50(3.142) = 307.8 = 98(3.142) [The Volume of the larger cylinder]
696212
find the common denominator\nmultipy the top and bottom of the fraction so the denominators are equal and then add the numerator
1154468
make a common denominator\n\na/b - c/d = a*d/b*d - c*b/d*b = (a*d-c*b)/b*d
894614
PV=nRT\nP= (nRT)/V  (1st eq)\n\nn,R,T u know.\n\nV >>>\nDensity = mass/ volume\n2.3 = .00446 *10^3/Volume\n\nrearrange and ull get volume.............and then put that into the first equation.............and voila
93955
change mixed fractions to proper fractions and then divide,\nwhats so hard?
181915
set up variables for everything.\n\nFor example: 7200 cars.  3200 four seaters.  then the rest is 7200-3200=4000 six seaters.  the 4 seaters are 100% full so 40000 people.  the total is 80% full thats 80%*(4000*6 + 3200*4) etc