Question

Afla nr a, b, c daca; a+b=c;a-b=b;b+c=20

Answer 1

a + b = c

a - b = b

b + c = 20

a = ?

b = ?

c = ?

a - b = b => a = b + b = 2b

a + b = c

2b + b = c

3b = c

c = 3b

b + c = 20

b + 3b = 20

4b = 20

b = 20 : 4

b = 5

a = 2b

a = 2 * 5

a = 10

c = 3b

c = 3 * 5

c = 15