Question

a+b+c=72 a=b+3 c=3•a a=? b=? c=?

Answer 1

Răspuns:

b+3=a=>b=a-3

a+(a-3)+3a=72

a+a-3+3a=72

5a=72+3

5a=75

a=15

b=12

c=45

Answer 2

Răspuns:

a+b+c=72

a=b+3

c=3•a=>c=3(b+3)=>c=3b+9

b+3+b+3b+9=72

5b=72-12=>b=60:5=>b=12

a=12+3=>a=15

c=3·15=>c=45

verificare: 15+12+45=72