(5×20分之7-4分之1)÷8=(4分之7-4分之1)÷8=2分之3÷8=16分之3
(5×7/20-1/4)÷8=3/2×1/8=3/16.
(7/20X5-1/4)÷8=(7/4-1/4)÷8=6/4÷8=3/16