Odpowiedź :
Odpowiedź:
Szczegółowe wyjaśnienie:
2.3
a)
1/8 + 2/18 + 3/24 = 1/8 + 1/9 + 1/8 = 2/8 + 1/9 = 1/4 + 1/9 = 9/36 + 4/36 = 13/36
b)
1/2 - 1/3 - 1/4 = 6/12 - 4/12 - 3/12 = - 1/12
c)
1/2 - (1/3 - 1/4) = 1/2 - 1/3 + 1/4 = 3/4 - 1/3 = 9/12 - 4/12 = 5/12
d)
1/2 - 1/3 • 1/4 = 6/12 - 1/12 = 5/12
e)
(1/2 : 2/3) : 3/4 = (1/2 • 3/2) • 4/3 = 1/3 • 4/3 = 4/9
f)
1/2 :( 2/3 : 3/4) = 1/2 • 3/2 • 4/3 = 3•4/2•2•3 = 1
2. 4
a) 0,4= 4/10 =2/5
b) 0,45 = 45/100 = 9/20
c) 0,08 = 8/100 = 2/25
d) 0,375 = 375/1000 = 15 /40 = 3/8
2,5
a) 2/3 = 0,666666..., = 0,(6)
b) 5/7 = 0,714285714285..., = 0,(714285)...,
c) 11/90 = 1,222222 =1,1(2)
Zad. 2.3
[tex]a) \\\\\frac18+\frac2{18}+\frac3{24}=\frac{9}{72}+\frac{8}{72}+\frac{9}{72}=\frac{26}{72}={\frac{13}{36}\\[/tex]
[tex]b) \\\\\frac12-\frac13-\frac14=\frac{6}{12}-\frac{4}{12}-\frac{3}{12}=\frac6{12}-\frac7{12}=-\frac1{12}[/tex]
[tex]c) \\\\\frac12-(\frac13-\frac14)=\frac6{12}-(\frac{4}{12}-\frac{3}{12})=\frac6{12}-\frac1{12}=\frac5{12}[/tex]
[tex]d)\\\\\frac12-\frac13*\frac14=\frac6{12}-\frac1{12}=\frac5{12}[/tex]
[tex]e) \\\\(\frac12:\frac23):\frac34=(\frac12*\frac32)*\frac43=\frac34*\frac43=1[/tex]
[tex]f) \\\\\frac12:(\frac23:\frac34)=\frac12:(\frac23*\frac43)=\frac12:\frac89=\frac12*\frac98=\frac9{16}[/tex]
Zad. 2.4
[tex]a) \\\\0.4=\frac4{10}=\frac25\\\\b) \\\\0.45=\frac{45}{100}=\frac9{20}\\\\c) \\\\0.08=\frac8{100}=\frac2{25}\\\\d) \\\\0.375=\frac{375}{1000}=\frac38[/tex]
Zad. 2.5
[tex]a)\\\\\frac23=0.(6)\\\\b) \\\\\frac57=0.(714285)\\\\c)\\\\\frac{11}{90}=0.1(2)[/tex]