SOLUTION: I am having trouble solving the following problem 1/A= 1/b + 1/c A= 3 B= 5 Find c So, 1/3=1/5+1/c Those are all fractions. what should I do?

Algebra ->  Trigonometry-basics -> SOLUTION: I am having trouble solving the following problem 1/A= 1/b + 1/c A= 3 B= 5 Find c So, 1/3=1/5+1/c Those are all fractions. what should I do?      Log On


   

Question 223391: I am having trouble solving the following problem
1/A= 1/b + 1/c
A= 3
B= 5
Find c
So, 1/3=1/5+1/c
Those are all fractions.
what should I do?
Answer by Earlsdon(6294) About Me  (Show Source):
You can put this solution on YOUR website!
Given:
1%2FA+=+1%2FB+%2B+1%2FC and:
A = 3
B = 5
Make the appropriate substitutions:
1%2F3+=+1%2F5%2B1%2FC Subtract 1%2F5 from both sides.
1%2F3-1%2F5+=+1%2FC Subtract the fractions on the left side, the LCD is 15.
5%2F15-3%2F15+=+1%2FC Simplify.
2%2F15+=+1%2FC Multiply both sides by C.
2C%2F15+=+1 Multiply both sides by 15.
2C+=+15 Finally, divide both sides by 2.
highlight%28C+=+7.5%29
Check:
1%2FA+=+1%2FB%2B1%2FC Substitute A = 3, B = 5, and C = 7.5
1%2F3+=+1%2F5%2B1%2F7.5 Put all of the fractions over the LCD of 15.
5%2F15+=+3%2F15%2B2%2F15
5%2F15+=+5%2F15 OK!