SOLUTION: If 1/3 + 1/x = 1/7, then find the value of x.

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Question 474650: If 1/3 + 1/x = 1/7, then find the value of x.
Answer by MathLover1(20849) About Me  (Show Source):
You can put this solution on YOUR website!

If 1%2F3+%2B+1%2Fx+=+1%2F7, then the value of x will be:
+1%2Fx+=+1%2F7-1%2F3

+1%2Fx+=+1%2A3%2F%287%2A3%29-1%2A7%2F%283%2A7%29

+1%2Fx+=+3%2F21-7%2F21

+1%2Fx+=+-4%2F21.....cross multiply

+1%2A21+=+-4%2Ax

+21%2F-4+=+x

-+5.25+=+x

check:

1%2F3+%2B+1%2Fx+=+1%2F7

1%2F3+%2B+1%2F-+5.25+=+1%2F7

0.33+-+0.19+=+0.14

0.14+=+0.14