Question

Se dau nr. a,b,c astfel incat.
a x(b+c)=5
c x(b+c)=15
c-a=2
Aflati a+c.

Answer 1

c×(b+c) - a×(b+c) = 15-5
(c-a)×(b+c) = 10
2×(b+c) = 10
b+c = 5

a = 1
c = 3
a+c = 4