B. TỰ LUẬN (3,0 điểm)

(1,0 điểm) Thực hiện phép tính;

a) \(\left( { - \frac{3}{4} + \frac{2}{7}} \right):\frac{4}{9} + \left( { - \frac{1}{4} + \frac{5}{7}} \right).{\left( {\frac{3}{2}} \right)^2}\);

b) \({\left( { - \frac{3}{4}} \right)^2}.0,16 - \sqrt {\frac{{16}}{{25}}} :\frac{{16}}{9} + {\left( { - 2024} \right)^0}\).

 

a) \(\left( { - \frac{3}{4} + \frac{2}{7}} \right):\frac{4}{9} + \left( { - \frac{1}{4} + \frac{5}{7}} \right).{\left( {\frac{3}{2}} \right)^2}\)

\( = \left( { - \frac{3}{4} + \frac{2}{7}} \right).\frac{9}{4} + \left( { - \frac{1}{4} + \frac{5}{7}} \right).\frac{9}{4}\)

\( = \left( { - \frac{3}{4} + \frac{2}{7} - \frac{1}{4} + \frac{5}{7}} \right).\frac{9}{4}\)

\( = \left[ {\left( { - \frac{3}{4} - \frac{1}{4}} \right) + \left( {\frac{5}{7} + \frac{2}{7}} \right)} \right].\frac{9}{4}\)

\( = \left[ { - 1 + 1} \right].\frac{9}{4}\)

\( = 0.\frac{9}{4}\)

\( = 0.\)

b) \({\left( { - \frac{3}{4}} \right)^2}.0,16 - \sqrt {\frac{{16}}{{25}}} :\frac{{16}}{9} + {\left( { - 2024} \right)^0}\)

\( = \frac{9}{{16}}.0,16 - \sqrt {{{\left( {\frac{4}{5}} \right)}^2}} .\frac{9}{{16}} + 1\)

\( = \frac{9}{{16}}.\frac{4}{{25}} - \frac{4}{5}.\frac{9}{{16}} + 1\)

\( = \left( {\frac{4}{{25}} - \frac{4}{5}} \right).\frac{9}{{16}} + 1\)

\( = \left( {\frac{4}{{25}} - \frac{{20}}{{25}}} \right).\frac{9}{{16}} + 1\)

\( = \frac{{ - 16}}{{25}}.\frac{9}{{16}} + 1\)

\( = \frac{{ - 9}}{{25}} + 1\)

\( = \frac{{16}}{{25}}.\)