BANTU DOOOONG TEMAN TEMAN T_T

Mapel : Matematika
Kelas : IX SMP
Bab : Bentuk akar

Pembahasan :
√[9 - 6√2]
= √[6 + 3 - 2√18]
= √[6 + 3 - 2√(6.3)]
= √6 - √3

Maka...
a - b = 6 - 3 = 3

Jawaban : C

[tex]\displaystyle \sqrt{9-6\sqrt2}=\sqrt{9-2\cdot3\sqrt2}\\\sqrt{9-6\sqrt2}=\sqrt{9-2\sqrt{9\cdot2}}\\\sqrt{9-6\sqrt2}=\sqrt{9-2\sqrt{18}}\\\sqrt{9-6\sqrt2}=\sqrt{(6+3)-2\sqrt{6\cdot3}}\\\\\text{bentuk khusus :}\sqrt{(a+b)-2\sqrt{ab}}=\sqrt{a}-\sqrt{b};a\ \textgreater \ b\\\\\sqrt{9-6\sqrt2}=\sqrt{6}-\sqrt3\\\\\therefore\\a-b=6-3\\\boxed{\boxed{a-b=3}}[/tex]