Thực hiện phép tính a) -9/17 + 6,72 + -8/17 + ( -4,72)

13/17

Thực hiện phép tính

a) \(\frac{{ - 9}}{{17}} + 6,72 + \frac{{ - 8}}{{17}} + \left( { - 4,72} \right)\).

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

c) \({\left( { - \frac{1}{3}} \right)^2} - \frac{3}{8}:{\left( {\frac{1}{2}} \right)^3} - \frac{5}{2} \cdot \left( { - 2} \right)\).

d) \(4,1 \cdot \frac{{ - 5}}{{12}} - 6,2 + 4,1 \cdot \frac{{ - 7}}{{12}}\).

Nhập câu trả lời ở đây

0/3000 ký tự

Giải thích

a) \(\frac{{ - 9}}{{17}} + 6,72 + \frac{{ - 8}}{{17}} + \left( { - 4,72} \right)\)

\( = \left( {\frac{{ - 9}}{{17}} + \frac{{ - 8}}{{17}}} \right) + \left( {6,72 - 4,72\;} \right)\)\( = \left( { - 1} \right) + 2 = 1.\)

b) \(2\frac{1}{5} - \left( {\frac{{ - 3}}{4} + \frac{1}{5}} \right)\)

\( = \frac{{11}}{5} + \frac{3}{4} - \frac{1}{5}\)\( = \left( {\frac{{11}}{5} - \frac{1}{5}} \right) + \frac{3}{4}\)\( = 2 + \frac{3}{4} = \frac{{11}}{4}.\)

c) \({\left( { - \frac{1}{3}} \right)^2} - \frac{3}{8}:{\left( {\frac{1}{2}} \right)^3} - \frac{5}{2} \cdot \left( { - 2} \right)\)

\( = \frac{1}{9} - \frac{3}{8}:\frac{1}{8} + \frac{5}{2} \cdot 2\)

\( = \frac{1}{9} - \frac{3}{8} \cdot \frac{8}{1} + 5 = \frac{1}{9} - 3 + 5\)

\( = \frac{1}{9} + 2 = \frac{{19}}{9}\)

d) \(4,1 \cdot \frac{{ - 5}}{{12}} - 6,2 + 4,1 \cdot \frac{{ - 7}}{{12}}\)

\( = 4,1 \cdot \left( {\frac{{ - 5}}{{12}} + \frac{{ - 7}}{{12}}} \right) - 6,2\)

\( = 4,1 \cdot \left( { - 1} \right) - 6,2\)

\( = \left( { - 4,1} \right) - 6,2\)

\( = - 10,3.\)