The value of a certain fraction becomes 1/5 if one is added to its numerator. If one is taken away from its denominator, its value becomes 1/7. Find the fraction.
Use an algebraic equation. Thanks!

Respuesta :

Answer:

[tex]\frac{2}{15}[/tex]

Step-by-step explanation:

Let the original fraction be [tex]\frac{x}{y}[/tex]

Then adding 1 to the numerator gives

[tex]\frac{x+1}{y}[/tex] = [tex]\frac{1}{5}[/tex] ( cross-  multiply )

⇒ y = 5x + 5 → (1)

Subtracting 1 from the denominator gives

[tex]\frac{x}{y-1}[/tex] = [tex]\frac{1}{7}[/tex] (cross-  multiply )

y - 1 = 7x → (2)

Substitute y = 5x + 5 into (2)

5x + 5 - 1 = 7x ← subtract 5x from both sides

4 = 2x ⇒ x = 2

Substitute x = 2 into (1)

y = (5 × 2) + 5 = 10 + 5 = 15

Hence original fraction = [tex]\frac{2}{15}[/tex]