(2 2/5: 1,2)×7/8+1 1/8: 2 (4,5-1/3): 2/9-(3,5+1/3)-4 1/2

(2 2/5:1,2)×7/8+1 1/8:2=2(5/16)=2,3125

1) 2(2/5)÷1,2=(12/5)÷(12/10)=(12×5×2)/(5×12)=2

2) 2×(7/8)=(2×7)/(4×2)=7/4

3) 1(1/8)÷2=(9/8)÷2=(9×1)/(8×2)=9/16

4) (7/4)+(9/16)=(7×4+9)/16=(28+9)/16=37/16=2(5/16)=2,3125

(4,5-1/3):2/9-(3,5+1/3)-4 1/2=10(5/12)~10,417

1) 4,5-(1/3)=(45/10)-(1/3)=(45×3-1×10)/30=(135-10)/30=125/30=4(5/30)=4(1/6)

2) 4(1/6)÷(2/9)=(25/6)÷(2/9)=(25×3×3)/(3×2×2)=(75/4)=18(3/4)

3) 3,5+(1/3)=(35/10)+(1/3)=(35×3+1×10)/30=(105+10)/30=(115/30)=3(25/30)=3(5/6)

4) 18(3/4)-3(5/6)=(75/4)-(23/6)=(75×3-23×2)/12=(225-46)/12=179/12=14(11/12)

5) 14(11/12)-4(1/2)=(179/12)-(9/2)=(179-9×6)/12=(179-54)/12=125/12=10(5/12)=10,416666667~10,417