Question

1. a)

kreska ulamkowa / =

b)

(kreska ułamkowa) /

c)

(kreska ulamkowa) /

2) Wiedzac, że a=3/16 i b+ 9/10, oblicz:

a) a-b (kreska ułamkowa) / a:b =

3. Oblicz:

(2 4/5 - 1,9) : 3 3/4 (kreska ulamkowa) / [ 3 1/6 - _ 1,25] * 2,4 - 5,8 =

Answer 1

b/     7²¹-7¹⁹/ 49⁹=  7²¹-7¹⁹/(7²)⁹=  7²¹-7¹⁹/7¹⁸= 7²¹-7¹⁹-¹⁸= 7²¹-7¹=7·7²⁰-7=7(7²⁰-1)   lub

        (7²¹-7¹⁹)/49⁹=(7¹⁹·7²-7¹⁹)/(7²)⁹= { 7¹⁹(7²-1)}/7¹⁸= 7(7²-1)=7(49-1)=7·48=336

 

c/  (3¹⁸+3¹⁶)·27/(3¹⁴+3¹²)·9=(3¹⁶·3²+3¹⁶)·3³/(3¹²·3²+3¹²)·3²=3¹⁶(3²+1)·3³/3¹²(3²+1)·3²=3¹⁶+³(3²+1)/ 3¹²+²(3²+1)=3¹⁹/3¹⁴=3¹⁹-¹⁴=3⁵

 

2/  a= 3/16,    b=9/10

     a-b= 3/16-9/10= 3·10/160 - 9·16/160= 30/160- 144/160= - 114/160= - 67/80

 

     a:b= 3/16: 9/10= 3/16·10/9= 30/144=15/72

 

      a-b/a:b= (3/16-9/10)/(3/16:9/10)=(3·10/160 - 9·16/160)/(3/16·10/9)=(30/160- 144/160)/30/144=

      -114/160:15/72= -67/80: 15/72= -67/80·72/15=-67/40·36/15=- 67·36/40·15=2412/600=           4 i 12/600=  4 i 1/50.

 

3/    (2 4/5-1,9):3,34 / (3 1/6-1,25)·2,4-5,8= (2,8-1,9):3,34/ {(3,17-1,25)·2,4-5,8}=0,9:3,34/(1,92·2,4-5,8)=0,27/(4,61-5,8)=0,27/(-1,19)=-0,23