Question

aflati nr. a b c d din egalitatile:
a:3+b:3=21
c:3+d:3=13
a+21=b
c:3=d:3+3

Answer 1

a=b-21;
⇒[b-21]/3+b/3=21
⇒b/3+7+b/3=21
⇒b/3+b/3=21-7
⇒b/3+b/3=14
⇒2b/3=14
⇒b=3·14/2
⇒b=3·7⇒b=21;
⇒a=21-21⇒a=0;
⇒c/3=d/3+3
⇒d/3+3+d/3=13
⇒d/3+d/3=13-3
⇒d/3+d/3=10
⇒2d/3=10
⇒d=3·10/2
⇒d=3·5⇒d=15;
⇒c/3=15/3+3
⇒c/3=5+3
⇒c/3=8
⇒c=24;

Answer 2

a;3+b;3=21
a+b=21x3x3=198
a+b=198
c+d=13x3x3=117
b=198-21=177
dupa calculezi si tu