The denominator of a rational numbers is twice it’s numerator if the numerator is decreased by 3 and the denominator increased by 7 the number obtained is 2/5 find the rational number

Respuesta :

Answer:

[tex]\frac{29}{58}[/tex]

Step-by-step explanation:

let x be the numerator of the rational number then 2x is the denominator

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

subtracting 3 from numerator and adding 7 to denominator , gives

[tex]\frac{x-3}{2x+7}[/tex] = [tex]\frac{2}{5}[/tex] ( cross- multiply )

5(x - 3) = 2(2x + 7) ← distribute parenthesis on both sides )

5x - 15 = 4x + 14 ( subtract 4x from both sides )

x - 15 = 14 ( add 15 to both sides )

x = 29

rational number = [tex]\frac{29}{58}[/tex]