perbandingan c. x:y:z = 2:7:5 dan 3x-2y+4z=72

•°. Jawaban :

x : y : z = 2 : 7 : 5

[tex] \frac{x}{y} = \frac{2}{7} [/tex]

[tex] \frac{y}{z} = \frac{7}{5} [/tex]

[tex] \frac{x}{z} = \frac{2}{5} [/tex]

nilai x, y dan z =

[tex] \frac{x}{y} = \frac{2}{7} [/tex]

[tex] = > x = \frac{2}{7} y[/tex]

[tex] \frac{y}{z} = \frac{7}{5} [/tex]

[tex] = > z = \frac{5}{7} y[/tex]

bila dimasukkan dlam persamaan =

3x - 2y + 4z = 72

[tex]3 \binom{2}{7} y - 2y + 4 \binom{5}{7} y = 72[/tex]

[tex] \frac{6y}{7} - 2y + \frac{20}{7}y = 72 [/tex]

pembagian pecahan dgn cara mengalikan 7 =

[tex] \binom{ 6y}{7} - 2y + \binom{20}{7} y \times 7 = 72 \times 7[/tex]

[tex]6y - 14y - 20y = 504[/tex]

[tex]12y = 504[/tex]

[tex]y = \frac{504}{12} [/tex]

y = 42

dan nilai x =

[tex]x = \frac{2}{7} y \\ x = \frac{2}{7}(42)[/tex]

x = 12

juga nilai z =

[tex]z = \frac{5}{7} y \\z = \frac{5}{7}(42)[/tex]

z = 30

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•°. Kesimpulan :

x = 42

y = 12

z = 30

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