MR-889 / 14d. problem

Simplify the following expression:

2a-23ab-3-4÷4a-23b-3-3·112a5b-2

2a-23ab-3-4÷4a-23b-3-3·112a5b-2

=2b33a·a2-4÷4b33a2-3·b212a5

=3a32b34÷3a24b33·b212a5

=34a3·424b3·4÷33a2·343b3·3·b212a5

=81a1216b12÷27a664b9·b212a5

=81 a1216 b12·64 b927 a6·b212a5

=3a6·41·b212a5

=12b212

=b2