tolong di jawab ya?

21. TIx = 10 log I/Io
[tex] = 10 log( \frac{ 10 {}^{ - 6} }{ 10 {}^{ - 12} } ) \\ = 10 log(10 {}^{6} ) \\ = 10 \times 6 \\ = 60[/tex]

TIy = TIx + 10 log (rx/ry)^2
[tex] = 60 + 10 log ( \frac{1}{10} ) {}^{2} \\ = 60 + 10 log( \frac{1 }{10 {}^{2} } ) \\ = 60 + 10 log(10 {}^{ - 2} ) \\ = 60 + 10 \times ( - 2) \\ = 60 - 20 \\ = 40 [/tex]

TIx : TIy = 60 : 40 = 3 : 2 (B)

22.
[tex]fp = \frac{v}{v + vs} \times fs \\ = \frac{390}{390 + 10} \times 400 \\ = \frac{390}{400} \times 400 = 390 \: hz \: [/tex]
jawabannya (B)