\(a,\left(a^2-ab+7\right)\left(\dfrac{1}{3}a-2\right)\)
\(=\dfrac{1}{3}a^3-2a^2-\dfrac{1}{3}a^2b+2ab+\dfrac{7}{3}a\)
\(b,\left(2x-1\right)\left(3x+2\right)\left(3-x\right)\)
\(=\left[\left(2x-1\right)\left(3x+2\right)\right]\left(3-x\right)\)
\(=\left(6x^2+x-2\right)\left(3-x\right)\)
\(=18x^2-6x^3+3x-x^2-6+2x\)
\(=-6x^3+16x^2+5x-6\)
a) ( a\(^2\) -ab +7 ) ( \(\dfrac{1}{3}\) .a -2 )
= \(\dfrac{1}{3}\) . a\(^3\) - 2a\(^2\) - \(\dfrac{1}{3}\) . a\(^2\)b + 2ab + \(\dfrac{7}{3}\) .a - 14
b) ( 2x -1 ) ( 3x +2 ) ( 3 - x )
= [(2x - 1)( 3x + 2 )] ( 3 - x )
= ( 6x\(^2\) + 4x - 3x - 2 ) (3 - x)
= 18x\(^2\) - 6x\(^3\) + 12x - 4x\(^2\) -9x + 3x\(^2\) - 6 + 2x
= -6x\(^3\) + 17x\(^2\) + 5x - 6
