Thực hiện phép tính: a) ( {3x - 2} ^2                    

a

   \[{\left( {3x - 2} \right)^2}\]

\[ = {\left( {3x} \right)^2} - 2 \cdot 3x \cdot 2 + {2^2}\]

\[ = 9{x^2} - 12x + 4.\]

b

   \[\left( {8{a^3}{b^4} - 6{a^2}b + 5{a^2}{b^2}} \right):\left( {2{a^2}b} \right)\]

\[ = 8{a^3}{b^4}:\left( {2{a^2}b} \right) - 6{a^2}b:\left( {2{a^2}b} \right) + 5{a^2}{b^2}:\left( {2{a^2}b} \right)\]

\[ = 4a{b^3} - 3 + \frac{5}{2}b.\]

c

   \[\left( {x - 3} \right)\left( {5{x^2} - 3x - 1} \right)\]

\[ = 5{x^3} - 3{x^2} - x - 15{x^2} + 9x + 3\]

\[ = 5{x^3} - 18{x^2} + 8x + 3.\]