со скидкой:
=8,400
=15%
↓
=
1000
15
×8,400
=0.15×8,400
=1,260
=8,400−1,260 = 7140
+15%
7,140
100
×7,140
=0.15×7,140
=1,071
=7,140+1,071
=8,211