Question

Afla valoare a b c stiind ca
a+b=30
a+c=40
b+c=50

Answer 1

A+b=30;b+c=50

A+b+b+c=80

80-40×(a+c)=40×(b+b)

b=40:2

b=20.

a=30-20

a=10.

10+c=40

c=40-10

c=30.

..............

Answer 2

a+b=30

a+c=40

b+c=50

a+b+a+c+b+c=30+40+50

2a+2b+2c=120

2(a+b+c)=120

a+b+c=120:2

a+b+c=60

30+c=60

c=60-30

c=30

b+30=50

b=50-30

b=20

a+20=30

a=30-20

a=10

proba:

10+20=30

10+30=40

20+30=50