if y varies inversely as x, and y=12 when x=6, what is K, the variation constant?
819723
"y varies inversely as x" means y = k/x, where k is the variation constant.  When x =6, y=12.  Plug those numbers in to get\n\n12 = k/6\nNow solve for k:  k=72, that is the value of the variation constant.
851885
You have :\n | x+4y   =12\n | 2x-3y  =6\n<=>\n | 2x+8y=24  \n | 2x-3y=6              \n<=>  \n | 11y=18\n | x+4y=12\n<=>\n | y=18/11\n | x=12-4(18/11)=60/11\n\nFinally, we have (x=60/11) and (y=18/11) .\n ^_^
284416
For inverse var.,\n\ny=k/x\n9=k/4, so k=36.
107222
If you mean "solve FOR y" then the answer is -\n12 y = 10-7 =3\ny = 3/12 = 1/4\n\nIf you meant "solve 4y (i.e. find the value of 4y)" then the answer is (similar technique to the previous one)-\n4y = 4*(1/4) = 1
687486
Both of the variables cannot be squared.  Since it opens to the left, the y variable is squared.\n(y-k)^2=-4p(x-h)\nk = 2 and h = 1\n(y-2)^2 = -4p(x-1)\nUsing the point (-1,-2), you can solve for y (you could also use the other point (-1,6)).\n(-2-2)^2 = -4p(-1-1)\n(-4)^2 = -4p(-2)\n16 = 8p\n2 = p
198253
y is 3 multiplied by x so if x is 1 y will be 3\n                             x is 2 y will be 6\n                             x is 3 y will be 9\n and so on
381503
there is direct and indirect variation, direct is y=kx and indirect is xy=k or y=k/x.  the constant of varitaion is k, which determines what x and y are.  normally they will tell you x or y and k, and ask you to find the other variable.
948239
xy = y^½\n y = y^½ /x\n y = y^½*x^-½\n\ndy/dx = -½ y^½ x^ -3/2\ndy/dx = - [½ y^½ ]/x^+3/2\ndy/dx = - (y^½) / (2x^3/2)
904136
if x+y = 5 and 2x+y =6, then x = 1 ( by subtracting two equations)\nif x =1, then y = 4\n\nthus x -y = 1-4 = - 3\n\ncool :)
735022
There will be a term proportional to distance added to a constant delay term, so the form will be t=kD + c. Solving for k and c:\nt1=.152=100k + c\nt2=.229=170k + c\nt2-t1=.077=70k\nThen k=.0011\nt1=.152=.11 + c --> c=.042\nt2=.229=.187 + c --> c=.042\nResult is\nt=.0011*D + .042
929836
v = b - u/k\nv - b = u/k\nk(v-b) = u
790053
The x component is 12 cos 60 and the y componet is 12 sin 60.\n\nThat is x component is 6N and y component is 10.4 N
794182
What nicknamr said, and also, the vertex would be located at the x-value found for the axis of symmetry, and the y-value for that x-value.  So, -b/(2a) = -12/(2 x -1) = 6.  Then, y= -(6)^2 + 12(6) -32 = -36 + 72 -32 = 4.  The vertex comes out to be (6,4).  (I would have answered all the other stuff too, but he already did it, and I found it rather redundant to repeat it all, so I just added on to it =)  )
859781
It says y varies inversely as the square of x.  This means that you can write an equation for it:\n\ny = k/x^2\n\nwhere k is the proportionality constant.\n\nYou're told that y = 7.2 when x = 10, so solve the equation for k:\n\nk = yx^2\n\nand plug in:\n\nk = 7.2(10^2) = 720.\n\nSo your equation is\n\ny = 720/x^2\n\nNow plug in:\n\n20 = 720/x^2\n\nx^2 = 720/20 = 36\n\nx = 6 (positive or negative 6, actually, but take the answer you think most reasonable).
421674
y = (x mod 5) + 1.\n\nThough that does seem a bit like cheating :)
339722
when X vries inversely as the square root of Y,\nX = k/sqrtY for some constant k\nX, when Y=3, is\nX = k/sqrt3\nX = ksqrt3/3\nand Y, when X=6, is\nk/sqrtY = 6\n6 sqrt Y = k\n36Y = k^2\nY = k^2/36\n\n^_^
380912
When dealing with inverse variation there are two different equations you can use, y= k/x or first y/new y= new x/ first x. So in this case you can either do I= k/d^2 then do I= k/2d^2 and compare the I's. Another way you can do it is I original/ I new= 2d^2/ d^2 then you compare the first I and the second I. Unfortunetly in this case you dont have numbers so you just look at the fact that in the firt equation your dividing by the d^2 or the 2d^2 and you look that in the first one your just dividing by d^2 or 12 inches, while in the second your dividing by 2d^2 or 4d or 24 inches, which is more. Then when you divide by more than the I is smaller or lest intense.