\(=\left(\frac{6\times5}{3}-\frac{7}{6}\times\frac{6}{7}\right):\left(\frac{21}{5}\times\frac{10}{11}+\frac{57}{11}\right)\)
\(=\left(10-1\right):\left(\frac{42}{11}+\frac{57}{11}\right)\)
\(=\left(10-1\right):\frac{99}{11}=9:9=1\)
2546790459 + 73547373841 + 7624881974 + 478658926
= (2546790459 + 73547373841) + (7624881974 + 478658926)
= 76094164300 + 8103540900
= 84197705200
2546790459 + 73547373841 + 7624881974 + 478658926
=(2546790459 + 73547373841) + (7624881974 + 478658926)
= 76094164300 + 8103540900
= 84197705200