Question

Determina nr a, b, c stiind ca a+b=700 ;b+c=500;a+c=800

Answer 1

a+b=700
b+c=500
a+c÷800
a+a+b+b+c+c=700+500+800
2 (a+b+c)=2000
a+b+c=1000
a=1000-500=500
b=1000-800=200
c=1000-700=300

Answer 2

a+b=700 ;b+c=500;a+c=800
(a+b)+(b+c)+(a+c)=700+500+800
2xa+2xb+2xc=2000; deoarece a+a=2xa,2 de b si 2 de c
dam factor comun pe 2 si obtinem:
2x(a+b+c)=2000
a+b+c=2000:2
a+b+c=1000
inlocuim sumele date si aflam numerele:
a+b+c=1000
700+c=1000
c=1000-700
c=300
a=1000-500=500
b=1000-800=200
Verificare: 500+200+300=1000
Raspuns: 500,200,300