Môn Toán Lớp 6: 30: x;45 :x và x10 9:(x2) (x 17):(x3) giúp mik vs ạ

Question

Môn Toán Lớp 6:  30: x;45 :x và x>10  9:(x+2) (x + 17):(x+3) giúp mik vs ạ

ankim · Answer

a)     30  vdots x; 45  vdots x     &rArr; x&isin;Ư(30;45)      Ta c&oacute;:      30=2.3.5     45=3^2 .5     &rArr; ƯCLN(30;45) =3.5 =15     &rArr; ƯC(30;45)=Ư(15) ={1;3;5;15}     V&igrave; x>10     &rArr; x=15     Vậy, x=15.     b)          9  vdots x+2     &rArr; x+2 &isin;Ư(9) ={&plusmn;1;&plusmn;3;&plusmn;9}     &rArr; x&isin;{-1;-3;1;-5;7;-11}     Vậy, x&isin;{-1;-3;1;-5;7;-11}.     c)          x+17  vdots x+3     &rArr; (x+17)/(x+3) = ( (x+3)+14 )/(x+3) = 1 + 14/(x+3)     &rArr; 14  vdots x+3     &rArr; x+3 &isin;Ư(14) ={&plusmn;1;&plusmn;2;&plusmn;7;&plusmn;14}     &rArr; x&isin;{-2;-4;-1;-5;4;-10;9;-17}     Vậy, x&isin;{-2;-4;-1;-5;4;-10;9;-17}.      $#nhatminhbuithien2010$

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