Tolong bantuin dong please, Pake Cara ya , No 20, 21, 22 sama 24

Tolong bantuin dong please, Pake Cara ya , No 20, 21, 22 sama 24

Jawaban Terkonfirmasi

Nomor 20

$$begin{align} left( 4sqrt{27}+3sqrt2 right)left( 4sqrt3-sqrt2 right)&=16sqrt{81}-4sqrt{54}+12sqrt6-3sqrt4\&=144-12sqrt6+12sqrt6-6\&=144-6\&=boxed{138} bold{(c.)} end$

Nomor 21

$$begin{align} frac{3+2sqrt2}{sqrt5-sqrt3}&=frac{3+2sqrt2}{sqrt5-sqrt3}timesfrac{sqrt5+sqrt3}{sqrt5+sqrt3}\&=frac{3sqrt5+3sqrt3+2sqrt{10}+2sqrt6}{5-3}\&=frac{3sqrt5+3sqrt3+2sqrt{10}+2sqrt6}{2}\&=boxed{frac{1}{2}left( 3sqrt5+3sqrt3+2sqrt{10}+2sqrt6 right)} bold{(b.)} end$