Question

[Dang the anh]

ba so x ; y ;z thoa man x-y = 8 ; y-z = 10 ; x+z = 20 . Tinh tong x+ y+ z 

Answer 1

[Isaac Newton]

Tổng x+y+z=(8+10+20):2=19

Answer 2

[Đinh Đức Hùng]

(x - y) + (y - z) + (x + z) = 8 + 10 + 20

2x = 38

=> x = 19

=> 19 - y = 8 => y = 11

=> 11 - z = 10 => x = 1

Vậy x = 19; y = 11; z = 1