9/10×2.7+6.3÷10/9+0.9

问题描述:

9/10×2.7+6.3÷10/9+0.9

9/10×2.7+6.3÷10/9+0.9
=9/10×2.7+6.3×9/10+9/10
=9/10×(2.7+6.3+1)
=9/10×10
=9