能简算的要简算三道4分之3x9分之7+0.75x9分之22.5x1.25x3249.5-17.25-2.25

4分之3x9分之7+0.75x9分之2
=3/4x(7/9+2/9)
=3/4x1
=3/4
2.5x1.25x32
=2.5x4x(1.25x8)
=10x10
=100
49.5-17.25-2.25
=49.5-(17.25+2.25)
=49.5-19.5
=30