17分之12 乘 9分之7 + 17分之12 除以 2分之9
=12/17x7/9+12/17x2/9
=12/17x(7/9+2/9)
=12/17x1
=12/17 (17分之12)
59 乘 19分之10 + 19分之9 除以 59分之1
=10/19x50+9/19x50
=(10/19+9/19)x50
=1x50
=50
17分之12 乘 9分之7 + 17分之12 除以 2分之9
=12/17x7/9+12/17x2/9
=12/17x(7/9+2/9)
=12/17x1
=12/17 (17分之12)
59 乘 19分之10 + 19分之9 除以 59分之1
=10/19x50+9/19x50
=(10/19+9/19)x50
=1x50
=50