Respuesta :

31.f(x) ={3x, x≤1

{2x, 1< x

= 3+1+2+1=7

= x+x+x =3x

= 3x+7=10x

= ×=30

=

10

= 3

now ,

3x=3

x≤1=3×1=3

2x=1×3×1×3=9

1<x=9×3=27,,,,,,,,

how I have done do of all number

note:please understand and write