if 4 is subtracted from the numerator of a fraction its value becomes 1/3 if 5 is added to the denominator of the original fraction its value becomes 1/2 what is the original fraction
Answers
Answer:
7/9
Step-by-step explanation:
let the numerator be x and denominator be y
when 4. is subtracted
x-4/y=1/3
3x-12=y
3x-y=12
x/y+5=1/2
2x=y+5
2x-y=5
by elimination method
x=7
substituting x =7 in 2x-y=5
2×7-y=5
14-y=5
-y=5-14
-y =-9
y=9
therefore the fraction is x/y
=7 /9
.
Step-by-step explanation:
Let the numerator of the original fraction be 'x' and the denominator be 'y'. So, the original fraction becomes x\y
According to the question,
Condition I,
If 4 is subtracted from the numerator of a fraction, its value becomes 1/3.
or,x−4\ y=1\3
or,3(x−4)=y
or,y=3x−12
Condition II,
If 5 is added to the denominator of the original fraction, the value becomes 1/2.
or,x\y+5=1\2
or,2x=y+5
Put value of y from equation (i) in equation (ii), we get,
or,2x=(3x−12)+5
or,2x=3x−12+5
or,3x−2x−7=0
∴x=7
Put value of x in equation (i), we get,
or,y=3×7−12
or,y=21−12
y=9
So, (x,y) = (7,9)
thus, the required original fraction is 7\ 9.