Question

daca a-b=7;
a+b+2c=53,
b+c=?
adauga la rezultatul obt numarul 899;
noul rezultat rotunjeste-l la zeci si sute

Answer 1

a-b=7⇒a=7+b
inlocuim  in a+b+2c=53
7+b+b+2c=53
2b+2c=53-7
2(b+c)=46
b+c=46/2
b+c=23
23+899=922
rotunjirea la zeci: 920
rotunjirea la sute:900