Question

A.suma a doua nare este 918 iar unul dintre ele este909 diferente dintre numere este ......
B.daca a+2b+3c=41si 5a+4b+3c=55 atunci a+b+c este .......

Answer 1

a. a+b=918;
a+909=918⇒a=9;
⇒b-a=909-9=900⇒diferenta dintre numere;
b. a+2b+3c=41;
5a+4b+3c=55
⇒[5a+4b+3c]-[a+2b+3c]=55-41
⇒4a+2b+0=14⇒4a+2b=14⇒2a+b=7⇒a=3⇒b=1;⇒a=2⇒b=3;⇒a=1⇒b=5;
⇒3+2+3c=41⇒3c=36⇒c=12;
⇒a+b+c=3+1+12=16;
⇒15+4+3c=55⇒3c=36⇒c=12⇒adevarat;
⇒2+6+3c=41⇒3c=33⇒c=11;
⇒a+b+c=2+3+11=16;
⇒10+12+3c=55⇒3c=33⇒c=11⇒adevarat;
⇒1+10+3c=41⇒3c=30⇒c=10;
⇒a+b+c=1+5+10=16;
⇒5+20+3c=55⇒3c=30⇒c=10⇒adevarat;
⇒a+b+c=16⇒adevarat;