(8分之3+15分之1)×8+15分之7
=3/8×8+1/15×8+7/15
=3+(8/15+7/15)
=3+1
=4
4分之3×9分之5-9分之1×4分之3
=3/4×(5/9-1/9)
=3/4×4/9
=1/3
5分之2÷7+7分之1×15分之8
=2/5×1/7+1/7×8/15
=1/7×(2/5+8/15)
=1/7×14/15
=2/15
(8分之3+15分之1)×8+15分之7
=3/8×8+1/15×8+7/15
=3+(8/15+7/15)
=3+1
=4
4分之3×9分之5-9分之1×4分之3
=3/4×(5/9-1/9)
=3/4×4/9
=1/3
5分之2÷7+7分之1×15分之8
=2/5×1/7+1/7×8/15
=1/7×(2/5+8/15)
=1/7×14/15
=2/15