d)3(x-4)-(8-x)=12
help tôi:a,x/8=3/4+ -5/8 b,x/12=3/4+ -2/3 c,1+11/3=24/x d,x/6-3/4=1/12
cần ngay bây giờ
a; \(\dfrac{x}{8}\) = \(\dfrac{3}{4}\) + \(\dfrac{-5}{8}\)
\(\dfrac{x}{8}\) = \(\dfrac{1}{8}\)
\(x\) = \(\dfrac{1}{8}\) \(\times\) 8
\(x\) = 1
b; \(\dfrac{x}{12}\) = \(\dfrac{3}{4}\) + \(\dfrac{-2}{3}\)
\(\dfrac{x}{12}\) = \(\dfrac{1}{12}\)
\(x\) = \(\dfrac{1}{12}\) \(\times\) 12
\(x\) = 1
c; 1 + \(\dfrac{11}{3}\) = \(\dfrac{24}{x}\)
\(\dfrac{14}{3}\) = \(\dfrac{24}{x}\)
\(x\) = 24 : \(\dfrac{14}{3}\)
\(x\) = \(\dfrac{36}{7}\)
d; \(\dfrac{x}{6}\) - \(\dfrac{3}{4}\) = \(\dfrac{1}{12}\)
\(\dfrac{x}{6}\) = \(\dfrac{1}{12}\) + \(\dfrac{3}{4}\)
\(\dfrac{x}{6}\) = \(\dfrac{5}{6}\)
\(x\) = \(\dfrac{5}{6}\) \(\times\) 6
\(x\) = 5
Câu a7/8 chia đóng ngoặc 2/9 - 18 đóng ngoặc + 7/8 x 1/36 - 5/12 câu b 3/7 x 4/9 + 3/7 x 5/9 chia 6/12 câu c 5^8 x 16/31 - 5^8 x 47/31 + 1/3 câu d 7/2 x 3/8 + 7/2 x 5/8 chia 4/15
a: =7/8:(2/9-18+1/36)-5/12
=-7/142-5/12=-397/852
b: =3/7(4/9+5/9:6/12)=2/3
c: =5^8(16/31-47/31)+1/3=-5^8+1/3
d: =7/2(3/8+5/8:4/15)=609/64
4. Tìm x € N , biết. A, 402 + ( x - 2 • 64 ) : 430 B, x : 12 và 12 x < 50 C, 12 • ( x - 1 ) : 3 = 4 + 2 D, 27 • 5 = 675 E, 3 + 3 = 36 G, 8 : x + 2 • ( x < 6 )
tính
a. -3/4 x 12/-5 x (-25/6)
b. -2 x -38/21 x -7/4 x (-3/8)
c. (11/12: 33/16) x 3/5
d. 7/23 x [(-8/6)- 45/18]
a. -3/4 x 12/-5 x (-25/6)=-15/2
b. -2 x -38/21 x -7/4 x (-3/8)=-19/8
c. (11/12: 33/16) x 3/5=4/15
d. 7/23 x [(-8/6)- 45/18]=-7/6
a. -3/4 x 12/-5 x (-25/6)=-15/2
b. -2 x -38/21 x -7/4 x (-3/8)=-19/8
c. (11/12: 33/16) x 3/5=4/15
d. 7/23 x [(-8/6)- 45/18]=-7/6
Bài 1: Tìm x:a) x - 2 + 7 = 1 . 3 . -9 b) 4 . x - 1 = (-5) 5 12 2 4 16 9 2 9c) -2 . x + 5 = 7 d) 2 . x : 7 . 1 = 29 3 8 12 5 3 8 15Bài 2: Tính:a) 2 + 1 . 4 b) 0,8 : [ 4 . 1,25] - [ 0,64 - 1 ] 5 7 5 25--------------------- 8 - 1 : 3 2 5 c) 8 : [ 7 - 12 ] d) ( 1,08 - 2 ) : 4 + ( 59 - 13 ). 36 9 2 7 25 7 9 4 17----------------------- [ 5 - 1 ] : 4
1) so sánh phân số
a) -8/12 và -3/-4 b)-56 /24 và 7/3 c) -4/25 và 15/-13
2) tính
a) 3/5 x 20/ -9
b)4/15 + -3/2 +8/-5
c) 19/35 x -38/7
d) -7/12 x 13/14 +1/14 x (-7) /12
Bài 1:
a: -8/12<0<-3/-4
b: -56/24<0<7/3
c: 4/25<1<15/13
=>-4/25>-15/13
Bài 2:
a: =-60/45=-4/3
b: =4/15-3/2-8/5=8/30-45/30-48/30=-85/30=-17/6
Tìm x
a,(x-7)+(5-x)=12-(-8)+x
b,3.(x-4)-(8-x)=12
c,4.(x-5)-3.(x+7)= -19
d,7.(x-3)-5.(3-x)=11.(x-5)
e,7.(x-9)-5.(6-x)=-6+11.x
***c,4(x-5)-3(x+7)=-19
Suy ra (4x-20)-(3x+21)=-19
Suy ra (4x-3x)-(20+21)=-19
Suy ra x-41=-19
suy ra x=-19+41
Suy ra x=22
Vậy x=22
2 tính : a) 1+1/4+1/8+1/16 =
=
b) 2-1/8-1/12-1/16 =
=
c) 4/99 x 18/5 : 12/11 + 3/5 =
=
d) ( 1-3/4 ) x ( 1+ 1/3 ) : ( 1- 1/3 ) =
=
a) 1 + 1/4 + 1/8 + 1/16
= 16/16 + 4/16 + 2/16 + 1/16
= 23/16
b) 2 - 1/8 - 1/12 - 1/16
= 96/48 - 6/46 - 4/48 - 3/48
= 83/48
c) 4/99 × 18/5 : 12/11 + 3/5
= 8/55 : 12/11 + 3/5
= 2/15 + 3/5
= 2/15 + 9/15
= 11/15
d) (1 - 3/4) × (1 + 1/3) : (1 - 1/3)
= 1/4 × 4/3 : 2/3
= 1/3 : 2/3
= 2
1 + 1/4 + 1/8 + 1/16
= 16 + 4 + 2 + 1 / 16
=23/16
2-1/8-1/12-1/16
= 96 - 6 - 4 - 3 / 48
= 83 / 48
4/99 x 18/5 : 12 /11 + 3/5
= 4/99 x 18/5 x 11/12 + 3/5
= 2/15 + 3/5
= 11/15
(1 - 3/4) x (1+1/3) : (1-1/3)
= 1/4 x 4/3 : 2/3
= 1/4 x 4/3 x 3/2
= 1/2