What is the component value in tda2030a circuit???

I like build some power amp with ST TDA2030A
problem is some component values are didn't mentioned
In the attached data-sheet page 7 figure:14 circuit diagram, R5 and C8 component value didn't mentioned
In the page 13 TABLE:2 R5 and C8 components are mentioned some equations and I didn't understand
what was that ? plzzz help meeeeeeeeeeeeeeeeeee

The table says that R5 should be 3 times the value of R2.
C8 controls the upper frequency cutoff and is 1 divided by (2 * pi * the max frequency you want * R1).

They don't explain why R5 and C8 are optional. Maybe to cut high frequency response so the amplifier is not unstable at AM radio broacast band frequencies.