600-476÷17×4
=600-28×4
=600-112
=488
12.6÷0.3-2.1×15
=42-31.5
=20.5还有呢...30÷【（2/3+1/5）×3/13】
=30÷（13/15×3/13）
=30÷1/5
=150还有一道qvq答完采纳~（3/4+1/3）÷13/18×1/3
=13/12÷13/18×1/3
=3/2×1/3
=1/2