159×5/6+159÷6
=159/6×5+159/6
=159/6×(5+1)
=159/6×6
=159
12×(2/15-1/12)×75%
=(2/15×12-1/12×12)×75%
=(8/5-1)×3/4
=3/5×3/4
=9/20
159×5/6+159÷6
=159/6×5+159/6
=159/6×(5+1)
=159/6×6
=159
12×(2/15-1/12)×75%
=(2/15×12-1/12×12)×75%
=(8/5-1)×3/4
=3/5×3/4
=9/20