2.25×4.8+77.5×0.48
=2.25×4.8﹢7.75×10×0.48
=2.25×4.8﹢7.75×4.8
=(2.25+7.75)×4.8
=10×4.8
=48
63×9分之7-9分之2×63
=63×(7/9-2/9)
=63×1
=63
4÷2分之1×（8分之5-4分之1）
=8×(5/8-1/4)
=8×5/8-8×1/4
=5-2
=3
（17分之8+13分之8）×8分之13×8分之17
=8/17×13/8×17/8+8/13×13/8×17/8
=13/8+17/8
=30/8
=15/4