Question

Se considera numerele naturale a,b,c. a) Daca a-b =215si b -c =132,determinati a-c. b) Daca a-c=138 si b- c =129, calculati a-b. c) Daca a-b =72 si (a-c) -(b-c) =18 , determinati numarul c.

Answer 1

a)  

( a - b ) + ( b - c ) = 215 + 132

a - b + b - c = 347

a - c = 347

_______________________

b)

( a - c ) - ( b - c ) = 138 - 129

a - c - b + c = 9

a - b = 9

_____________________________

c)

( a - c ) - ( b + c ) = 18

a - c - b - c = 18

( a - b ) - 2 c = 18

72 - 2 c = 18

2 c = 72 - 18

2 c = 54

c = 54 : 2

c = 27