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2014-09-13T12:50:23+03:00
20% din a= 80% din b

20/100 * a = 80/100 * b

1/5 * a=20/25 *b

a/5= 20b/25

a= 5*20b/25= 20b/5= 4b

a=4b

a) p% din a= b

p/100 * a=b

p/100*4b=b

p/25 *b=b

p=25%

c)a² +b²=17

(4b)² +b²=17

16b²+b²=17

17b²=17

b²=1  => b=1

a=4*1=4
3 5 3