If 1/x + y =5 and x + 1/y =8 , what is the ratio of x to y?
605260
Multiply the first equation by x, multiply the second equation by -y, then add the two equations together.\n1 + xy = 5x\n-xy - 1 = -8y\n0 = 5x - 8y\nAdd 8y to each side\n8y = 5x\nDivide both sides by 5y\n8/5 = x/y\nAnswer: 8/5
951394
x+y=4\nx-y=8.5\n\nJust add the 2 equations\n\nit will result to this one:\n\n2x-0y=12.5\n2x=12.5\nx=6.25\n\nusing x, we could get the value of y.just choose from the 2 given equations where you  could substitute x.\n\nx+y=4\n6.25+y=4\ny= -2.25
413999
In step 4 you divided by (a-b) which is zero.\n\nIf you could do this you could just say that 5 times 0 = 8 times 0 means that 5 = 8, by dividing both sides by 0 and canceling it.
919613
Divide 1 by 2/5 or \n1/(2/5) = 5/2
404472
from 4/5 to /10?\nYou multiply both by 2.\n4 x 2 and 5 x 2 \nSo u get 8/10
556363
(8/x+2) + (8/2) = 5\n\n(8/x+2) + 4 = 5\n\nSubtract 4\n\n(8/x+2)=1\n\nMultiply x+2\n\n8= x+2\n\nSubtract 2\n\nx=6
204054
x:y=5:3=k,then x=5k,y=3k\n5x+3y=5*5k+3*3k=34k,3x+5y=15k+15k=30k\nso the answer is 34k/30k=17/15 (k<>0)
709514
Here's how, using #8 as an example\n\n5/8 = x/100  \n\n(always use x/100 because percent means divided by 100)\n\ncross multiply 8x = 500\n\ndivide 500 by 8 which is 62.5So it is 62.5 %
1010836
Convert the 5/8 to 10/16 by multiplying by 2/2.  Then add the 1/16.\n\n5/8 + 1/16 =\n( 2/2 * 5/8 ) + 1/16 =\n10/16 + 1/16 =\n11/16.
421674
y = (x mod 5) + 1.\n\nThough that does seem a bit like cheating :)
926120
your variable is x so you replace that with 8, since x=8     since there are no signs between the 9 and x  in  9x  , that means to multiply them  so that is 72       so your answer is 72 + 5 or 77  , hope that helps
795190
y = ax^3\n-5 = -8a, 5 = 8a, a = 5/8\n\nf(x) = (5/8)x^3
805022
let the numbers be x and y\nSo x + y = 7\nxy = 25\n\nNow 1/x + 1/y \n= x/xy + y/xy\n= (x + y)/xy\n= 7/25\n\nx + y = 7 So y = 7 - x\nxy = 25\n\nSo x(7 - x) = 25\n\n7x - x² = 25\n x² - 7x + 25 = 0\nx = [-b ± √(b² - 4ac)]/(2a)\n= [7 ± √(7² - 4.1.25)]/(2)\n= [7 ± √(- 51)]/(2)\n\nSo x = [7 - √(- 51)]/(2) and y = [7 + √(- 51)]/(2) \nThus 1/x = 1/[7 - √(- 51)]/(2)\n= 2/[7 - √(- 51)] * [7 + √(- 51)]/[7 + √(- 51)]\n= 2[7 + √(- 51)]/(49 - -51)\n= [7 + √(- 51)]/50\n\n1/y = [7 - √(- 51)]/50\nSo 1/x + 1/y = [7 + √(- 51)]/50 + [7 - √(- 51)]/50\n= 14/50\n= 7/25 (as above but with much more effort!!!!!!!!) (8^O)
67769
Divide 8 into 3\n.375
788661
A ratio is equivalent to a fraction. When two ratios are equal, then it is known as a proportion. Solving ratios require this method of cross-mutilplication.\n\n(x + 10) + x : x + 10 = 21 : 18\n\n(x + 10) + x    /    x + 10   =   21 / 18  (/ = divide)\n\nNote: write the above on paper in fraction form and you should see better\n\nreduce 21:18 to the lowest factor by dividing by 3 which will be 7 : 6 .Then cross-multiply the two set of fractions.\n\n\n7(x + 10) = 6 (x + 10 + x)\n7x + 70 = 6x + 60 + 6x\n7x - 6x - 6x = 60 - 70\n-5x = -10\nx = 2
560796
x = 4/5 + 1 3/8\nx = 4/5 + 11/8\nx = 32/40 + 55/40\nx = 87/40\nx = 2 7/40
815841
x+y=7\nxy=25\n1/x+1/y=?\nif you add by making both denominators equal (gcf is xy) you get\n(y+x)/(xy)=7/25