Question

aflati 3 numere naturale a,b si c stiind ca sunt direct proportionale cu 2,4 si 7 iar 6a+3b-2c=180

Answer 1

{a;b;c}
{2;4;7}

$\frac{a}{2} = \frac{b}{4} = \frac{c}{7} = k$

$\frac{a}{2} = k$
a = 2k

$\frac{b}{4} = k$
b = 4k

$\frac{c}{7} = k$
c = 7k

6a + 3b - 2c = 180
6·2k + 3·4k - 2·7k = 180
12k + 12k - 14k = 180
24k - 14k = 180
10k = 180
k = 18

a = 2k = 2·18 = 36
b = 4k = 4·18 = 72
c = 7k = 7·18 = 126