Question

the sum of two rational numbers is 4/21 . If one of them is 5/7 , find the other
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Answer 1

Step-by-step explanation:

Let the required number be x. Then,

=(5/7)+x=(4/21)

By sending (5/7) from left hand side to the right hand side it change to −(5/7)

x=(4/21)−(5/7)

LCM of 21 and 7 is 21

Express each of the given rational numbers with the above LCM as the common denominator.

Now,

(21×1)

(4×1)

=

21

4

=

(7×3)

(5×3)

=

21

15

Then,

=(4/21)−(15/21)

=(4−15)/21

=(−11/21)

Hence the required number is (−11/21)

satisfied are you with the answer

Answer 2

-11/21 is the answer of the question

Step-by-step explanation:

they given sum of two rational numbers is 4/21

one of the number is 5/7

so,if a+b=c then c-a=b

then 5/7+x/y=4/21

so, 4/21-5/7=x/y

LCM of 21,7 is 21

so,5/7=5*3/7*3=15/21

4/21-15/21=4-15/21

so answer is -11/21