Toán Lớp 6: 1,-5/2:(3/4-1/2) 2,298/719:(1/4+1/12-1/3) 3,(27.18+27.103-120.27)/(15.33+33.12) 4,(x-5/8).5/18=-15/36 5,|x-1/3|=5/6

Question

Toán Lớp 6:  1,-5/2:(3/4-1/2)       2,298/719:(1/4+1/12-1/3)     3,(27.18+27.103-120.27)/(15.33+33.12)      4,(x-5/8).5/18=-15/36    5,|x-1/3|=5/6

maingoctruc · Answer

Giải đáp + Lời giải và giải thích chi tiết:   1. -5/2:(3/4-1/2)   =-5/2:(3/4-2/4)   =-5/2:1/4=-5/2*4=-10   2. 298/719:(1/4+1/12-1/3)   =298/719:(3/12+1/12-4/12)   =298/719:0 ( v&ocirc; l&yacute;, kh&ocirc;ng thể t&iacute;nh được v&igrave; mẫu phải kh&aacute;c 0 )   3. (27*18+27*103-120*27)/(15*33+33*12)   =[27(18+103-120)]/[33(15+12)]   =(27*1)/(33*27)=1/33   4. (x-5/8)*5/18=-15/36   =>(x-5/8)*5/18=-5/12   =>x-5/8=-5/12:5/18   =>x-5/8=-5/12*18/5   =>x-5/8=-3/2   =>x=-3/2+5/8   =>x=-12/8+5/8=-7/8   Vậy x = -7/8   5. |x-1/3|=5/6   => ( left[  begin{array}{l}x- dfrac{1}{3}= dfrac{5}{6}  x- dfrac{1}{3}=- dfrac{5}{6} end{array}  right. )   => ( left[  begin{array}{l}x= dfrac{7}{6}  x=- dfrac{1}{2} end{array}  right. )   Vậy x in {7/6;-1/2}.

annhocbichchaubich · Answer

1)   -5/2 : (3/4- 1/2)    = -5/2 : 1/4   =  -10   2)   298/719 : (1/4 + 1/12 - 1/3)    = 298/719 : (3/12 + 1/12 - 4/12)    = 298/719 : 0 (kh&ocirc;ng xảy ra)   3)   (27.18 + 27.103 - 120.27)/(15.33 + 33.12)    = (27 . (18 + 103 - 120))/(33 . (15+12))   = (27 . 1)/(33 . 27)    = 1/33   4)   (x-5/8) . 5/18 = -15/36   => x-5/8 = -15/36 : 5/18   => x - 5/8 = -3/2   => x = -3/2 + 5/8   => x = -7/8   Vậy x=-7/8   5)   |x-1/3| = 5/6   =>x - 1/3 = 5/6 hoặc x-1/3=-5/6   +) x - 1/3 = 5/6   => x = 5/6 + 1/3   => x = 7/6   +) x - 1/3 = -5/6   =>  x = -5/6 + 1/3   => x = -1/2   Vậy x  in {7/6 ; -1/2}