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Sprendimas:
Iš viso mokinių yra $$4+5+10+5+1 = 25$$
( 5* 4+ 6* 5+ 7* 10+ 8* 5+ 9* 1) |
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/ 25 |
=
( 5* 4+ 6* 5+ 7* 10+ 8* 5+ 9* 1) |
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/ 25 |
= $$\frac{5\cdot 4+6\cdot 5+7\cdot 10+8\cdot 5+9\cdot 1}{25}$$ = 
(20+ 6* 5+ 7* 10+ 8* 5+ 9* 1) |
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/ 25 |
= $$\frac{20+6\cdot 5+7\cdot 10+8\cdot 5+9\cdot 1}{25}$$ = 
(20+30+ 7* 10+ 8* 5+ 9* 1) |
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/ 25 |
= $$\frac{20+30+7\cdot 10+8\cdot 5+9\cdot 1}{25}$$ = 
(20+30+70+ 8* 5+ 9* 1) |
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/ 25 |
= $$\frac{20+30+70+8\cdot 5+9\cdot 1}{25}$$ = 
= $$\frac{20+30+70+40+9\cdot 1}{25}$$ = 
= $$\frac{20+30+70+40+9}{25}$$ = 
= $$\frac{50+70+40+9}{25}$$ = 
= $$\frac{120+40+9}{25}$$ = 
6.76$$6.76$$

Atsakymas: 6.76
19 uždavinys21 uždavinys