3.6+9.7+6.4
=3.6+6.4+9.7
=10+9.7
=19.7
4.67-（2.98+0.67）
=4.67-0.67-2.98
=4-2.98
=1.02
(4/5-3/4)÷ 2/5
=4/5÷2/5-3/4÷2/5
=2-15/8
=1/8
所以 5分之2/（5分之4-4分之3） ＝8
1/4x5/6+1/6x1/4
=1/4x(5/6+1/6)
=1/4x1
=1/4