4

∫

0

|x| + |x - 2| + |x - 4| dx
=

2

∫

0

f (x) dx +

4

∫

2

f (x) dx
=

2

∫

0

x - x + 2 - x + 4 dx +

4

∫

2

x + x - 2 - x + 4 dx
=

2

∫

0

6 - x dx +

4

∫

2

x + 2 dx
= |6x−

x2

2

|02 + |

x2

2

+2x|04
= 12 - 2 + 8 + 8 - 2 - 4 = 20