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Need help with a maths question
by Conor Lee Junior Cert Mathematics — 03/10/16 3

Here is a fraction: x over blank (x/ ) The denominator of the fraction is 5 more than the numerator. If 1 is added to the numerator and 2 is subtracted from the denominator, the fraction will become 4/5. Find the fraction. need the answer explained


3 Comments
Chris241197 — 09/09/16
x+1/x+5 =4/5 solve this equation Explained, if demon is 5 more : x/x+5 then add one and subtract 2 : x+1/x+5
clio_h — 10/09/16
numerator: x denominator: 5 more than x: x+5 current fraction: x/x+5 add 1 to the numerator: x + 1 subtract 2 from the denominator: x+5 -2 (which is x+3 because 5-2=3) so the fraction is now x+1/x+3 the question says that this new fraction is equal to 4/5 so x+1/x+3 = 4/5 cross multiply across the equal sign: (x+1)(5) = (x+3)(4) multiply out: 5x+5 = 4x+12 bring xs to the left and numbers to the right: 5x-4x = 12-5 x=7 now we know that x=7, so we can sub 7 into the original fraction given in the first two lines of the question: x/x+5 Sub in 7 anywhere that there is an x: 7/7+5 =7/12 is the fraction!
Amy.gallagher — 03/10/16
This is a simultaneous equation-a father and his son have a combined age of 52.8 years ago the father was 8 times the sons age .write and equation in x and y
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