Răspuns:
Ex.1
a) 5/3;33/7;33/12 /-->linia fractionara
b)37/5;22/5;165/20
Ex.2(43)
a)....=6/2
b)[tex]\frac{7}{12}*2+\frac{4}{6} *4+\frac{12}{24} =\frac{14}{24} +\frac{16}{24} +\frac{12}{24} =\frac{42}{24}[/tex]
c)[tex]\frac{24}{5} *(\frac{28}{40} *\frac{20}{63}-\frac{28}{30} /\frac{28}{25} )=\frac{24}{5} *(\frac{560}{2520}-\frac{1}{1.2} )=\frac{24}{5} *(-0.6(1))=\frac{24}{5}*\frac{1}{0.6(1)} =\frac{24}{3} =8[/tex]Ex.3(44)
a) 2-10,20
5-10,30,50
10-50,30,20
b)3-27,9,33
9-27,17,45
Ex.4(45)
16m...........8h
x m.............2h
Nr de muncitori si timpul sunt marimi invers proportionale
daca timpul scade , nr de muncitori trebuie sa creasca
Timpul scade de 4 ori (8h:4=2h)
Nr de muncitori creste de 4 ori, 16*4=64 muncitori
Pt o ora , nr de ore scade de 8 ori , rezulta ca nr de muncitori va creste de 8 ori adica 16*8=128 muncitori.
Ex.5(46)
a) zecimale---2,3;6,7;8,1
ordinare-4/8;1/2;7/9;3/4
b) zecimale-5,7
ordinare-4/5;9/10
Ex.6(47)
a)45/10;78/10;91/10;125/10
b)1213/100;642/100;7,8/10;115/100;1235/10
c)1134/100;345/100;4456/1000;12/10
Ex.7(48)
a)0,2;0,5;1,2;12,3
b)0,05;0,12;1,23
c)0,005;0,012;45,6
Explicație pas cu pas:
