a + b + c = 444 * 2 -78 = 888 -78 = 810
c = ( a + b ) : 2 sau 2*c =( a+b )
b = a * 5
inmultim prima ecuatie cu 2 si vom obtine :
2*a + 2* b+ 2* c = 810 *2
2a +2b +2c = 1620
acum inlocuim termenii
2a +10a + (a + b) =1620
2a + 10a +a +5a =1620
18a =1620
a = 1620 : 18
a = 90
b = a* 5
b = 90 * 5 = 450
c = (a+b ) : 2 = (90 +450 ) :2 =540 :2 =270
