Question

Determinați numerele naturale A,b,c știind că:
●a+b=100
b+c=110
a+c=90

Answer 1

Răspuns:

a=100-b

a=90-c

100-b=90-c

b-c=10

b+c=110

__________ +

2b / = 120 =>b=60 =>a=40 =>c=50

Answer 2

a + b = 100

b + c = 110

a + c = 90

a + b + b + c = 100 + 110

a + 2 × b + c = 210

90 + 2 × b = 210

2 × b = 210 - 90

2 × b = 120

b = 120 : 2

b = 60

a = 100 - b

a = 100 - 60

a = 40

c = 90 - a

c = 90 - 40

c = 50