Question

determine x.y.z e t sabendo que :
(x) (y) (20)
(y)+(z)=(15)
(z) (4) (9)

Answer 1

(x) (y) (20)                            x.y.z=0.15.0=0
x.15.20=0
300x=0
x=0

(y)+(z)=(15)
z=15-y
z=15-15
z=0

(z) (4) (9)
(15-y).4.9=
(15-y).36=
540-36y=
-36y=-540.(-1)
y=540/36
y=15