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Need help, badly.
Please help me for these math exercises.
I) If you take away the same number to the upper and the lower part of 4/5 (4 being the upper and 5 the lower) you obtain the number : 5/4.
What number is it that we took off the first number (4/5).
Clarifying :
4/5 - x/x = 5/4.
What is "x" ?
Please help me out.
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4/5 - x/x = 5/4
Into a decimal
0.80 - X = 1.25
to make the number bigger, X would need to be negative.
0.80 - (-X) = 1.25
What negative number if subtracted from 0.80 would equal 1.25?
0.80 - (-0.45) = 1.25
Back into a fraction
4/5 - 9/20 = 5/4
Ik, ghetto style, i generally don't follow the styles taught, i tend to make my own as I go :o.
EDIT: crap, i just realized something. x/x would mean that both of those numbers would have to be the same? if they do this doesn't make sense? Clarification please :)
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(4 - x) / (5 - x) = 5/4
Cross multiplying gives us 25 - 5x = 16 - 4x
Adding 5x to both sides yields 25 = 16 + x
Then, subtracting 16 gives us x = 9, which is the final answer.
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Quote:
Originally Posted by
mastaraymond
x/x = 1...
Wot
^total math major here:frusty:
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The question itself doesn't say 4/5 - x/x = 5/4 - that was something that Dervish assumed it meant.
Method's holds true as (4-9)/(5-9) = -5/-4 = 5/4 and also agrees with what the question mentioned about the same number being taken away from both the top and bottom.
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It equals 9 :).
Thanks alot method and all who posted :).