Question

fie a,b,c numere naturale pentru care a+b=120 si b+c=230.calculați:
a)a+2b+c
b)5a+8b+3c
ajutor!!!

Answer 1

a+b=120 rezulta a= 120-b sau a=120-b
b+c= 230 rezulta c=230- b sau b=230=c
a) a+2b+c=120-b+2b+230-b= 120+230-b+2b-b=350+b-b=350
b) 5a+8b+3c= 5(120-b) +8b+ 3(230-b)= 5ori120-5b+8b+3ori230-3b= 600-5b+8b+690-3b= 600+3b+690-3b= 600+690=1290