I: 0.5x-2.5z=1.2
II: z=2x-10z
with II:
z=2x-10z
0=2x-11z
11z=2x
(11/2)z=x
insert (11/2)z=x in I:
(1/2)*(11/2)z-(5/2)z=1.2
(11/4)z-(10/4)z=1.2
(1/4)z=1.2
z=4.8
35)
additionally to Atoney2001ou6e0i explanation, when changing the scale of something/its units you multiply it by a factor. In this case its all the side-lengths of the cube, because you want to scale the volume this factor is included three times, once for each axis.
1m=100 cm
1000[m³]=1000*(100)³[cm³]
=1000*1 000 000
=1 000 000 000=10⁹[cm³]
