{5又9分之5减去0.8+2又9分之4}乘以{7.6除以5分之4+2又5分之4乘以1.25},等于?

{5又9分之5减去0.8+2又9分之4}乘以{7.6除以5分之4+2又5分之4乘以1.25}
={5又9分之5+2又9分之4-0.8}×{7.6×5/4+2又5分之4×5/4}
=7.2×{(7.6+2又5分之4)×5/4}
=7.2×13
=93.6
题目是否打错,应该是:
5又9分之5减去0.8+2又9分之4}乘以{7.2除以5分之4+2又5分之4乘以1.25}
={5又9分之5+2又9分之4-0.8}×{7.2×5/4+2又5分之4×5/4}
=7.2×{(7.2+2.8)×5/4}
=7.2×10×5/4
=90

={5又9分之5+2又9分之4减去4/5}乘以{38/5除以5分之4+14/5乘以5/4}
=(8-4/5)X(19/2+7/2)
=36/5X13
=468/5
希望没算错口算。。。
望采纳~~