Question

daca 2a+b=22 si a+b=12
a)calculeaza 3a+2b
b)aflati a si b

Answer 1

a) 3a+2b= 22+12 = 34
b) a+b=12 | * (-2)
-2a-2b=-24
2a+b=22 .... + 
-b=-2 | * (-1)
b=2
a+2=12 | -2
a=10

Answer 2

a)2a+b=22 +

   a+b=12

__________

  3a+2b=22+12=34

a)2a+b=22 -

   a+b=12

__________

  2a-a+b-b=22-12⇒a=10

b=12-10=2 si b=22-2*10=2