Tính biểu thức hợp lí (nếu có thể): e) 15 /37 ⋅ ( 38 /41 − 74 /45 ) − 38/ 41 ⋅ ( 15/ 37 + 82 /76 ) ;
e) \(\frac{{15}}{{37}} \cdot \left( {\frac{{38}}{{41}} - \frac{{74}}{{45}}} \right) - \frac{{38}}{{41}} \cdot \left( {\frac{{15}}{{37}} + \frac{{82}}{{76}}} \right)\)
\( = \frac{{15}}{{37}} \cdot \frac{{38}}{{41}} - \frac{{15}}{{37}} \cdot \frac{{74}}{{45}} - \frac{{38}}{{41}} \cdot \frac{{15}}{{37}} - \frac{{38}}{{41}} \cdot \frac{{82}}{{76}}\)
\[ = \left( {\frac{{15}}{{37}} \cdot \frac{{38}}{{41}} - \frac{{38}}{{41}} \cdot \frac{{15}}{{37}}} \right) + \left( { - \frac{{15}}{{37}} \cdot \frac{{74}}{{45}} - \frac{{38}}{{41}} \cdot \frac{{82}}{{76}}} \right)\]
\[ = 0 + \left( { - \frac{1}{1} \cdot \frac{2}{3} - \frac{{38}}{{41}} \cdot \frac{{41 \cdot 2}}{{38 \cdot 2}}} \right)\]
\[ = \frac{{ - 2}}{3} - 1 = \frac{{ - 2 - 3}}{3} = - \frac{5}{3}\].