Question

Determination numerele x,y,z invers proportionale cu 2,3,4. Stiind ca x+y-z=7

Answer 1

Răspuns:

x+y-z=7(123)=145(1287)-67+76:89-612=1986-890=-138

Answer 2

Explicație pas cu pas:

$\dfrac{x}{ \dfrac{1}{2} } = \dfrac{y}{ \dfrac{1}{3} } = \dfrac{z}{ \dfrac{1}{4} }$

$2x = 3y = 4z = k$

$x = \dfrac{k}{2}; \ y = \dfrac{k}{3}; \ z = \dfrac{k}{4}$

$x + y - z = \dfrac{^{6)} k}{2} + \dfrac{^{4)}k}{3} - \dfrac{^{3)}k}{4}$

$\dfrac{6k + 4k - 3k}{12} = 7$

$\dfrac{7k}{12} = 7 \implies k = 12$

$x = \dfrac{12}{2} \implies x = 6\\ y = \dfrac{12}{3} \implies y = 4 \\ z = \dfrac{12}{4} \implies z = 3$