hasil dari pertanyaan tersebut adalah

f(x) = | 1-4x |

maka:
f(1) = | 1-4(1) |
= | -3 |
= 3
f(-3) = | 1-4(-3) |
= | 1-(-12) |
= 13

f(1) + 2f(-3) =
3 + 2(13) =
3 + 26 = 29

semoga membantu