Question

x -y-z sunt numere invers proportionale la 4.5.8 suma numereleo x si y =54

Answer 1

{x,y,z}ip{4,5,8}
x+y=54
Formam un sir de produse egale
4x=5y=8z=k
x=k/4
y=k/5
z=k/8
k/4+k/5=54
Aduci la acelasi numitor care este 20
9k/20=54
k=(54  x   20)/9=120
x=30
y=24
z=15

Answer 2

{x,y,z} IP {4,5,8} =>
4x=5y=8z= prin notatie cu k => x=k/4 ; y=k/5 si z=k/8
Dar x+y=54 => k/4+k/5= 54 => 9k/20=54 => 9k=1080 => k=120 =>
x=120/4 => x=30
y=120/5 => y=24
Z=120/8 => z=15