Question

Daca a+b=7 b+c=10 si c+a=13 cat este a+b+c?​

Answer 1

Răspuns:

a+b+b+c+a+c=7+10+13

2a+2b+2c=30

2(a+b+c)=30 =>a+b+c=15

7+c=15 =>c=15-7=8

a+10=15=>a=15-10=5

b=15-5-8 =>b=2

Explicație pas cu pas:

a=5

b=2

c=8

Verificare :

a+b=7

5+2=7

b+c=10

2+8=10

c+a=13

8+5=13