Question

Determinați nr x , știind ca 57 supra 31 - 16 supra 31 este egal cu x-21 supra 31

Answer 1

Răspuns:

x=62

Explicație pas cu pas:

Folosim formula:  

$\displaystyle\boxed{\frac{x}{y} -\frac{z}{y} =\frac{x-z}{y}}$

$\displaystyle\frac{57}{31} -\frac{16}{31} =\frac{x-21}{31} \\\\\\ \frac{57-16}{31} =\frac{x-21}{31}$

$\displaystyle\frac{41}{31} =\frac{x-21}{31}$

In aceasta faza aplicam urmatoarea egalitate

$\displaystyle\frac{x}{y} =\frac{z}{t} daca \ x\times t = y\times z$

$\displaystyle\frac{41}{31} =\frac{x-21}{31}$

$\displaystyle 41\times 31= 31\times (x -21 )\\\\ 41=x-21\\ \\ x=41+21\\ \\ x=62$