Відповідь:

Пояснення:

  #   a ) . . . =  3a²/( 5b ) * 10b²/( 6a ) = ab ;

       б ) . . . = ( x + 6 )(x - 6 ) * 6/[2( x - 6 ) ] = 3( x + 6 ) ;

       в ) . . . = 3( x² - 9 )/( 28x ) * 1/[ 2( x + 3 ) ] = 3(x - 3 )/( 56x ) .  

[tex]\displaystyle\bf\\1)\\\\\frac{3a^{2} }{5b} :\frac{6a}{10b^{2} } =\frac{3a^{2} }{5b} \cdot\frac{10b^{2} }{6a }=\frac{3a\cdot a\cdot 5b\cdot 2b}{5b\cdot 3a\cdot 2} =ab\\\\2)\\\\(x^{2} -36):\frac{2x-12}{6} =(x-6)\cdot(x+6)\cdot \frac{6}{2x-12} =\\\\\\=\frac{(x-6)\cdot(x+6)\cdot 6}{2\cdot(x-6)} =3\cdot(x+6)=3x+18\\\\3)\\\\\frac{3x^{2} -27}{28x} :(2x+6)=\frac{3\cdot(x^{2}-9) }{28x}\cdot\frac{1}{2\cdot(x+3)} =\\\\\\=\frac{3\cdot(x-3) \cdot(x+3)}{28x}\cdot\frac{1}{2\cdot(x+3)} =\frac{3x-9}{56x}[/tex]