Răspuns:
Explicație pas cu pas:
m=suma economisita de Maria
s=suma economisita de Sofia
[tex]m+s=1200\\\frac{25}{100} m+\frac{20}{100} s=276\\\\\left \{ {{m+s=1200\\} \atop {\frac{25}{100} m+\frac{20}{100} s=276\\\\}} \right. \\\\\frac{1}{4} m+\frac{1}{5} s=276\\\\\left \{ {{m+s=1200\\} \atop {\frac{1}{4} m+\frac{1}{5} s=276\\}} \right. \\\\\\[/tex]
