Răspuns :
Răspuns: 5a-2b+c=20
a=5 , b=5*2 =>b=10
c=a+b=> c=5+10 => c=15
5 x a - 2 x b + c = 5a -2b+c=5x5 - 2 x 10 + 15 =25-20+15=5+15=20
Răspuns: 5a-2b+c=20
a=5 , b=5*2 =>b=10
c=a+b=> c=5+10 => c=15
5 x a - 2 x b + c = 5a -2b+c=5x5 - 2 x 10 + 15 =25-20+15=5+15=20