Tržba v obchode

113400 = a+b+c+d
a=d
b = a + 1/10a
c = a - 5/100a

113400 = a+b+c+d
a=d
b = a + 1/10·a
c = a - 5/100·a

a+b+c+d = 113400
a-d = 0
11a-10b = 0
95a-100c = 0

Pivot: Riadok 1 ↔ Riadok 4
95a-100c = 0
a-d = 0
11a-10b = 0
a+b+c+d = 113400

Riadok 2 - 1/95 · Riadok 1 → Riadok 2
95a-100c = 0
1,0526c-d = 0
11a-10b = 0
a+b+c+d = 113400

Riadok 3 - 11/95 · Riadok 1 → Riadok 3
95a-100c = 0
1,0526c-d = 0
-10b+11,5789c = 0
a+b+c+d = 113400

Riadok 4 - 1/95 · Riadok 1 → Riadok 4
95a-100c = 0
1,0526c-d = 0
-10b+11,5789c = 0
b+2,0526c+d = 113400

Pivot: Riadok 2 ↔ Riadok 3
95a-100c = 0
-10b+11,5789c = 0
1,0526c-d = 0
b+2,0526c+d = 113400

Riadok 4 - 1/-10 · Riadok 2 → Riadok 4
95a-100c = 0
-10b+11,5789c = 0
1,0526c-d = 0
3,2105c+d = 113400

Pivot: Riadok 3 ↔ Riadok 4
95a-100c = 0
-10b+11,5789c = 0
3,2105c+d = 113400
1,0526c-d = 0

Riadok 4 - 1,05263158/3,21052632 · Riadok 3 → Riadok 4
95a-100c = 0
-10b+11,5789c = 0
3,2105c+d = 113400
-1,3279d = -37180,3279


d = -37180,32786885/-1,32786885 = 28000
c = 113400-d/3,21052632 = 113400-28000/3,21052632 = 26600
b = 0-11,578947368421c/-10 = 0-11,57894737 · 26600/-10 = 30800
a = 0+100c/95 = 0+100 · 26600/95 = 28000

a = 28000
b = 30800
c = 26600
d = 28000

Vypočítané naším kalkulátorom sústavy lineárnych rovníc.