Răspuns :
A+B+C=99, A+C=89 =>(inlocuid) 89 + B = 99
89 + 11 = 99 => B = 11
A= 100-50+3= 53
B=11
A-B= 42
89 + 11 = 99 => B = 11
A= 100-50+3= 53
B=11
A-B= 42
a=100-50+3 a=53 ; c+a=89 c+53=89 c=89-53 c=36 ;a+b+c=99 53+b+36=99 b=99-(53+36) b=99-89 b=10; a-b=? 53-10=43