[tex]a + b + c + d = 140000[/tex]
[tex]a = 4200[/tex]
[tex]b = 15 \times a[/tex]
[tex]c = \frac{a + b}{2} [/tex]
[tex]b = 15 \times a \\ b = 15 \times 4200 \\ b =63000 [/tex]
[tex]c = \frac{4200 + 63000}{2 } \\ c = \frac{67200}{2} \\ c = 33600[/tex]
[tex]d = 140000 - (4200 + 63000 + 33600) \\ d = 140000 - 100800 \\ d = 39200[/tex]
printr-un singur exercitiu
[tex]a + b + c + d = 140000 \\ 4200 + 15 \times 4200 + \frac{ 4200 + 15\times 4200}{2} + d = 1400 \\ 4200 + 63000 + \frac{4200 + 63000}{2} + d = 140000 \\ 4200 + 63000 + \frac{67200}{2} + d = 140000 \\ 4200 + 63000 + 33600 + d = 140000 \\ 100800 + d = 140000 \\ d = 140000 - 100800 \\ d = 39200[/tex]
[tex]b = 630000 \\ c = 33600 \\ d = 39200[/tex]
Am facut-o prin doua moduri. Succes!