=6×(8/ 15-7/ 15)

=6× 1/ 15

=2/5

(2)∵ 12.5%= 1/8

∴ Original formula =32× 1/8+28× 1/8

=60× 1/8

=7.5

(3)7/8x-3/4x=5/6

1/8x=5/6

x=20/3

(4) 1.6x=26.4

x= 16.5

(5) 1/6x= 15

x = 90°

(6)6×4000×70%×0.3%=50.4 yuan.

(7)100× (1+25%-1) = 25 (yuan)

(8)(2- 1.6)÷2=20%

(9)750( 1-40%-30%)= 2500 (m)

(10)1200× 2× 4.5 %× (1-5%)+1200 =1302.6 (yuan)

( 1 1) 1.

20%- 15%=5%

2.

36%-25%= 1 1%

(12) Pants: 270÷ (1+1.25) =120 (Yuan) Coat:125% ×120 =/.

(13)1600 ÷ (1-40%-40%) = 8000 (pieces)