[tex]830 - [(6 \times 4 + 6 \times 6) \div a] + 322 = 1146[/tex]
[tex]830 - (24 + 36) \div a = 1146 - 322[/tex]
[tex]830 - 60 \div a = 824[/tex]
[tex] - 60 \div a = 824 - 830[/tex]
[tex] - 60 \div a = - 6 \: | \times ( - 1)[/tex]
[tex]60 \div a = 6[/tex]
[tex]a = 60 \div 6[/tex]
[tex]a = 10[/tex]