Question

Determinati numerele naturale a,b,c stiind ca a,b,c sunt direct proportionale cu 3,7,8 si 2a + 5b - 4c=108

Answer 1

a/3 = b/7 = c/8 = k

a = 3k

b = 7k

c = 8k

Dar 2a + 5b - 4c = 108

2*3k + 5*7k - 4*8k = 108

6k + 35k - 32k = 108

9k = 108

k = 12

Atunci a = 3k = 36

b = 7k = 84

c = 8k = 96

Answer 2

Răspuns

a=36

b=84

c=96

Explicație pas cu pas:

(a;b;c)d.p(3;7;8)

a/3=b/7=c/8=k

a=3k

b=7k

c=8k

2*3k+5*7k-4*8k=108

6k+35k-32k=108

41k-32k=108

9k=108

k=108:9

k=12

a=12*3  => a=36

b=12*7  => b=84

c=12*8  => c=96

verificare:

2*36+5*84-4*96=

=72+420-384=

=492-384=

=108