Răspuns:
3.
a = suma de bani a primului frate
b = suma de bani al celui de al doilea frate
c = suma de bani al celui de al treilea frate
a + b + c = 6302
[tex] \frac{5a}{6} = \frac{b}{2} = \frac{5c}{7} = k[/tex]
=>
[tex]a = \frac{6k}{5}[/tex]
[tex]b = 2k[/tex]
[tex]c = \frac{7k}{5} [/tex]
[tex] \frac{6k}{5} + 2k + \frac{7k}{5} = 6302[/tex]
6k + 10k + 7k = 31510
23k = 31510
k = 1370 =>
a = 1644 lei
b = 2740 lei
c = 1918 lei
4.
a) A(1,a) € Gf => f(1) = a
f(1) = a+2 + a -3
=> a+2+a-3 = a
2a - 1 = a
a = 1
b) f(x) = 3x - 2
5)
[tex] \frac{a}{2} = \frac{b}{5} = k[/tex]
=> a = 2k , b = 5k
[tex] \frac{b}{10} = \frac{c}{7} [/tex]
=> 10c = 7b
b = 5k => 10c = 35k => c = 35k/10
[tex]c = \frac{7k}{2} [/tex]
a+b+c =420
[tex]2k + 5k + \frac{7k}{2} = 420[/tex]
[tex]7k + \frac{7k}{2} = 420[/tex]
14k + 7k = 840
21k = 840 => k = 40
a = 80
b = 200
c = 140
