Упростите выражение a^2-9/a^2-2a+4÷a+3/9a^3+72=

( a ^ 2 - 9 ) / ( a ^ 2 - 2 * a + 4 ) ÷ ( a + 3 ) / ( 9 * a ^ 3 + 72 ) ;( a ^ 2 - 9 ) / ( a ^ 2 - 2 * a + 4 ) * ( ( 9 * a ^ 3 + 72 ) / ( a + 3 ) ) ; ( a ^ 2 - 9 ) / ( a ^ 2 - 2 * a + 4 ) * ( 9 * ( a ^ 3 + 8 ) / ( a + 3 ) ) ;( a ^ 2 - 9 ) / ( a ^ 2 - 2 * a + 4 ) * ( 9 * ( a + 2 )* ( a ^ 2 - 2 * a + 4 ) ) / ( a + 3 ) ) ;( a ^ 2 - 9 ) / 1 * ( 9 * ( a + 2 )* 1 ) / ( a + 3 ) ) ; ( a - 3 ) * ( a + 3 ) / 1 * ( 9 * ( a + 2 )) / ( a + 3 ) ) ;( a - 3 ) * 1 / 1 * ( 9 * ( a + 2 )) / 1 ) ; ( a - 3 ) * 9 * ( a + 2 ) ;9 * ( a - 3 ) * ( a + 2 ).