Answer:
C)
Step-by-step explanation:
*Look at the picture*
Solve for e
d = 1/e + 1/f
Move 1/f to the left side of the = sign
d - 1/f = 1/e
Multiply each side by e
e(d - 1/f) = e(1/e)
e(d - 1/f) = 1
Divide out (d - 1/f)
e(d - 1/f) / (d - 1/f) = 1 / (d - 1/f)
e = 1 / (d - 1/f)
Answer:
(y - x)/(y + x)
Step-by-step explanation:
(1/x - 1/y)/(1/x + 1/y) =
= (1/x - 1/y)/(1/x + 1/y) × (xy)/(xy)
= (y - x)/(y + x)
The second choice is the right answer