Question

Se considera numerele reale a,b,c astfel incat a+2b=11 si +2c=16. Determinati: a) a+b-2c b) 2a+4b c) 3b+6c

Answer 1

daca se stie ca :   a + 2b =11  si   b+ 2c =16 , atunci:

a)...    a+2b - (b+2c) = a+2b-b-2c = a+b-2c = 11 - 16 = - 5 ;     

b)....  2a+4b = 2(a+2b)=2*11 = 22 ;

c)...   3b+6c = 3(b+2c) = 3*16 = 48 ;