Question

sabe-se que a+b=1200, a+c=1500 e b+c=1100. qual éo valor de a+b+c?

Answer 1

A + b = 1200
A = 1200 -b

A + c = 1500
1200 - b + c = 1500
C = 1500 - 1200 + b
C = 300 + b

B + c = 1100
B + 300 + b = 1100
2b = 1100 - 300
2b = 800
B = 800/2
B = 400

A + b = 1200
A + 400 = 1200
A = 1200 - 400
A = 800

A + c = 1500
800 + c = 1500
C = 1500 - 800
C = 700

Entao: a + b + c

800 + 400 + 700 = 1900