Question

6. Află numerele a, b, c, dacă:
a+b=c;
a - b=b;
b+c= 20.​

Answer 1

Răspuns:

a-b+a+b=20

2a=20

a=10

b+a+b=20

2b+10=20

2b=10

b=5

a-b+c=20

10-5+c=20

5+c=20

c=20-5

c=15

Verificare :

a+b=c

10+5=15

a-b=b

10-5=5

b+c=20

5+15=20