Answers

2015-03-14T15:16:15+05:30
Cost= 200 rs
length of the cable=x meter
then cost of one meter= \frac{200}{x}
length of the cable(if)= x+5
cost of one meter= \frac{200}{x+5}

we know that
 \frac{200}{x} - \frac{200}{x+5} =2 \\  \\ 
 \frac{200x+100-200x}{ x^{2} -5x} =2 \\  \\ 
 \frac{100}{ x^{2} -5x} =2 \\  \\ 
2 x^{2} -10x=100 \\ 
divide/all/terms/by/2 \\ 
 x^{2} -5x=50 \\ 
 x^{2} -5x-50=0 \\ 
(x-10)(x+5)=0 \\ 
x=10/ or/ x=-5 \\

length of the cable= 10 m
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2015-03-15T13:58:28+05:30
200/x-200/x+5=2    (/ means upon)
=200x+100-200x/x sq-5x=2
100/x sq-5x=2
2xsq-10x=2
x sq-5x = 50 (divide the terms by 2 )
x sq-5x-50=0
(x-10)(x+5)=0
x= 10,x=-5
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