I want to ask Maths

１. [(-7/3)÷(7/2)]/[(25/8)(-8/5)]
= (-7/3)(2/7)/-5
=-2/3

2. -5/3(0.5-2/3)÷[-1/2+1/(1+2/7)]
=.-5/3(1/2-2/3)÷[(1/2)/(9/7)]
=-5/3(-1/6)÷(7/18)
=5/36÷7/18
=5/14

3. 4/15÷(1/2.5-1/1.5)
=4/15÷(30/75-50/75)
=4/15÷(-20/75)
= -1

[(-7/3) ÷ (7/2)] ÷ [(25/8) (-8/5)]
= (-7/3 x 2/7) ÷ (25/8 x 8/5)
= -2/3 ÷ -5
= -2/3 x 1/-5
= 2/15


-5/3(0.5-2/3) ÷ [-1/2+1/ (1+2/7)]
= -5/3 ( 1.5/3 – 2/3 ) ÷ [ -1/2 + 1/ ( 1+ 2/7 )]
= -5/3 ( -0.5/3 ) ÷ [ -1/2 + 1/ (9/7) ]
= 2.5/9 ÷ [-1/2 + 1/ (9/7) ]
= 5/18 ÷ ( -9/18 + 14/18 )
= 5/18 ÷ 5/18
= 5/18 x 18/5
= 1

4/15 ÷ ( 1/2.5 – 1/1.5 )
= 4/15 ÷ ( 2/5 – 2/3 )
= 4/15 ÷ (6/15 – 10-15 )
= 4/15 ÷ -4/15
= - ( 4/15 x 15/4 )
= -1

1. [(-7/3)÷(7/2)]/[(25/8)(-8/5)]
=(-7/3)*(2/7)]/[-5]
=(-2/3)/(-5)
=-2/15

2. -5/3(0.5-2/3)÷[-1/2+1/(1+2/7)]
=-5/3(1/2-2/3)÷[-1/2+1/(9/7)]
=-5/3(-1/6)÷[-1/2+7/9]
=(5/18)÷[5/18]
=1

3. 4/15÷(1/2.5-1/1.5)
=(4/15)/(2/5-2/3)
=(4/15)/(-4/15)
=-1