6 + 5 X 3 + 12 =
Tính nhẩm
5 x 6 = ..... 2 x 6 = ..... 3 x 6 = ..... 4 x 6 = .....
6 x 5 = ..... 6 x 2 = ..... 6 x 3 = ..... 6 x 4 = .....
30 : 6 = ..... 12 : 6 = ..... 18 : 6 = ..... 24 : 6 = .....
30 : 5 = ..... 12 : 2 = ..... 18 : 3 = ..... 24 : 4 = .....
5 x 6 = 30 2 x 6 = 12 3 x 6 = 18 4 x 6 = 24
6 x 5 = 30 6 x 2 = 12 6 x 3 = 18 6 x 4 = 24
Tính nhẩm:
5 x 6 = 30 2 x 6 = 12 3 x 6 = 18 4 x 6 = 24
6 x 5 = 30 6 x 2 = 12 6 x 3 = 18 6 x 4 = 24
30 : 6 = 5 12 : 6 = 2 18 : 6 = 3 24 : 6 = 4
30 : 5 = 6 12 : 2 = 6 18 : 3 = 6 24 : 4 = 6
Học tốt <3
5 x 6 = 30 2 x 6 = 12 3 x 6 = 18 4 x 6 = 24
6 x 6 = 30 6 x 2 = 12 6 x 3 = 18 6 x 4 = 24
30 : 6 = 5 12 : 6 = 2 18 : 6 = 3 24 : 6 = 4
30 : 5 = 6 12 : 2 = 6 18 : 3 = 6 24 : 4 = 6
a) -12+(x-9)<0 tìm x thuộc Z
b)x-(13-x)=-24+(-7+x)
c) (x - 7)+( 5-x)=12-(-8+x)
d)5(x-6)-2(x+3)=12
e)3(x-4)-(8-x)=12
f) 7(x-3)-5(3-x)=11x-5
g) 7(x-9)-5(6-x)=-6+11x
a) -12+(x-9)<0 tìm x thuộc Z
b)x-(13-x)=-24+(-7+x)
c) (x - 7)+( 5-x)=12-(-8+x)
d)5(x-6)-2(x+3)=12
e)3(x-4)-(8-x)=12
f) 7(x-3)-5(3-x)=11x-5
g) 7(x-9)-5(6-x)=-6+11x
5/6 + 5/8 + 3/4
12/15 + 3 + 3/5
4/3 x 7/8 x 5
8/9 x 6/5 : 3
7/12 + 5/8 x 4/3 - 3/4
(8/5 - 7/6) : 13/15 + 1/4
bài 5: tính giá trị biểu thức sau một cách hợp lí
A = -7/21 + ( 1+1/3) B=2/15 +(5/9+ -6/9)
C=9-1/5 + 3/12 ) + -3/4
bài 6
a) x + 7/8 = 13/12 b) - (-6)/12 - x = 9/48
c) x+ 4/6 = 5/25 - (-7)/15 c) x + 4/5 = 6/20 - (-7)/3
`5`
`a, -7/21 +(1+1/3)`
`=-7/21 + ( 3/3 + 1/3)`
`=-7/21+ 4/3`
`=-7/21+ 28/21`
`= 21/21`
`=1`
`b, 2/15 + ( 5/9 + (-6)/9)`
`= 2/15 + (-1/9)`
`= 1/45`
`c, (9-1/5+3/12) +(-3/4)`
`= ( 45/5-1/5 + 3/12)+(-3/4)`
`= ( 44/5 + 3/12)+(-3/4)`
`= 9,05 +(-0,75)`
`=8,3`
`6`
`x+7/8 =13/12`
`=>x= 13/12 -7/8`
`=>x=5/24`
`-------`
`-(-6)/12 -x=9/48`
`=> 6/12 -x=9/48`
`=>x= 6/12-9/48`
`=>x=5/16`
`---------`
`x+4/6 =5/25 -(-7)/15`
`=>x+4/6 =1/5 + 7/15`
`=> x+ 4/6=10/15`
`=>x=10/15 -4/6`
`=>x=0`
`----------`
`x+4/5 = 6/20 -(-7)/3`
`=>x+4/5 = 6/20 +7/3`
`=>x+4/5 = 79/30`
`=>x=79/30 -4/5`
`=>x= 79/30-24/30`
`=>x= 55/30`
`=>x= 11/6`
\(5)\)
\(A=\dfrac{-7}{21}+\left(1+\dfrac{1}{3}\right)\)
\(A=\dfrac{-7}{21}+\dfrac{4}{3}\)
\(A=\dfrac{-7}{21}+\dfrac{28}{21}\)
\(A=1\)
\(--------------\)
\(B=\dfrac{2}{15}+\left(\dfrac{5}{9}+\dfrac{-6}{9}\right)\)
\(B=\dfrac{2}{15}+\dfrac{-1}{9}\)
\(B=\dfrac{18}{135}+\dfrac{-15}{135}\)
\(B=\dfrac{1}{45}\)
\(------------\)
\(C=9-\dfrac{1}{5}+\dfrac{3}{12}+\dfrac{-3}{4}\)
\(C=\dfrac{44}{5}+\dfrac{3}{12}+\dfrac{-3}{4}\)
\(C=\dfrac{528}{60}+\dfrac{15}{60}+\dfrac{-3}{4}\)
\(C=\dfrac{181}{20}+\dfrac{-3}{4}\)
\(C=\dfrac{181}{20}+\dfrac{-15}{20}\)
\(C=\dfrac{83}{10}\)
\(6)\)
\(a)\) \(x+\dfrac{7}{8}=\dfrac{13}{12}\)
\(x=\dfrac{13}{12}-\dfrac{7}{8}\)
\(x=\dfrac{104}{96}-\dfrac{84}{96}\)
\(x=\dfrac{5}{24}\)
\(b)\) \(\dfrac{-6}{12}-x=\dfrac{9}{48}\)
\(\dfrac{-1}{2}-x=\dfrac{3}{16}\)
\(x=\dfrac{-1}{2}-\dfrac{3}{16}\)
\(x=\dfrac{-8}{16}-\dfrac{3}{16}\)
\(x=\dfrac{-11}{16}\)
\(c)\) \(x+\dfrac{4}{6}=\dfrac{5}{25}-\left(-\dfrac{7}{15}\right)\)
\(x+\dfrac{4}{6}=\dfrac{5}{25}+\dfrac{7}{15}\)
\(x+\dfrac{4}{6}=\dfrac{75}{375}+\dfrac{105}{375}\)
\(x+\dfrac{4}{6}=\dfrac{12}{25}\)
\(x=\dfrac{12}{25}-\dfrac{4}{6}\)
\(x=\dfrac{72}{150}-\dfrac{100}{150}\)
\(x=\dfrac{-14}{75}\)
\(d)\) \(x+\dfrac{4}{5}=\dfrac{6}{20}-\left(-\dfrac{7}{3}\right)\)
\(x+\dfrac{4}{5}=\dfrac{6}{20}+\dfrac{7}{3}\)
\(x+\dfrac{4}{5}=\dfrac{18}{60}+\dfrac{140}{60}\)
\(x+\dfrac{4}{5}=\dfrac{79}{30}\)
\(x=\dfrac{79}{30}-\dfrac{4}{5}\)
\(x=\dfrac{79}{30}-\dfrac{24}{30}\)
\(x=\dfrac{11}{6}\)
Giải:
\(A=\dfrac{-7}{21}+\left(1+\dfrac{1}{3}\right)\)
\(A=\dfrac{-7}{21}+\dfrac{4}{3}\)
\(A=\dfrac{-7}{21}+\dfrac{28}{21}\)
\(A=\dfrac{21}{21}=1\)
\(B=\dfrac{2}{15}+\left(\dfrac{5}{9}+\dfrac{-6}{9}\right)\)
\(B=\dfrac{2}{15}+\dfrac{-1}{9}\)
\(B=\dfrac{6}{45}+\dfrac{-5}{45}\)
\(B=\dfrac{1}{45}\)
\(C=\left(9-\dfrac{1}{5}+\dfrac{3}{12}\right)+\dfrac{-3}{4}\)
\(C=\left(\dfrac{44}{5}+\dfrac{1}{4}\right)+\dfrac{-3}{4}\)
\(C=\dfrac{181}{20}+\dfrac{-3}{4}\)
\(C=\dfrac{181}{20}+\dfrac{-15}{20}\)
\(C=\dfrac{166}{20}\)
Bài 6:
\(a)x+\dfrac{7}{8}=\dfrac{13}{12}\)
⇔\(x=\dfrac{13}{12}-\dfrac{7}{8}=\dfrac{5}{24}\)
\(b)\dfrac{-6}{12}-x=\dfrac{9}{48}\)
⇔\(x=\dfrac{-6}{12}-\dfrac{9}{48}=\dfrac{-11}{16}\)
\(c)x+\dfrac{4}{6}=\dfrac{5}{25}-\dfrac{-7}{15}\)
\(\Leftrightarrow x+\dfrac{2}{3}=\dfrac{2}{3}\)
\(\Leftrightarrow x=\dfrac{2}{3}-\dfrac{2}{3}=0\)
\(d)x+\dfrac{4}{5}=\dfrac{6}{20}-\dfrac{-7}{3}\)
⇔\(x+\dfrac{4}{5}=\dfrac{79}{30}\)
⇔\(x=\dfrac{79}{30}-\dfrac{4}{5}=\dfrac{11}{6}\)
X x 2 và 2/3 = 3 và 4/8 + 6 và 5/12
1-x = 2 và 5/12 : 3 và 5/9
3 và 7/8 x X - 2 và 3/4 = 3 và 6/12 x 10/8 - 1/3
đây là hỗn số nhé các bạn
cái này not toán lớp 4
Bài 1 Tìm x,biết
x.3/5=2/3
x.7/17=17/8
3/4 chia x=-7/12
3/8 - 1/6.x=1/4
1/3+1/2 chia x=-4
Bài 2 Tính
-6/11 chia [3/5 . 4/11]
7/12 + 5/12 chia 6 -11/36
[4/5 + 1/2] chia [3/13 - 8/13]
[2/3 - 1/4 + 5/11] chia [5/12 + 1 -7/11]
*Dấu . là dấu nhân nha mn*
Bài 1:
a: \(x=\dfrac{2}{3}:\dfrac{3}{5}=\dfrac{2}{3}\cdot\dfrac{5}{3}=\dfrac{10}{9}\)
b: \(x=\dfrac{17}{8}:\dfrac{7}{17}=\dfrac{17}{8}\cdot\dfrac{17}{7}=\dfrac{289}{56}\)
c: \(x=-\dfrac{3}{4}:\dfrac{7}{12}=\dfrac{-3}{4}\cdot\dfrac{12}{7}=\dfrac{-63}{28}=-\dfrac{9}{4}\)
d: \(\Leftrightarrow x\cdot\dfrac{1}{6}=\dfrac{3}{8}-\dfrac{1}{4}=\dfrac{1}{4}\)
hay \(x=\dfrac{1}{4}:\dfrac{1}{6}=\dfrac{3}{2}\)
e: \(\Leftrightarrow\dfrac{1}{2}:x=-4-\dfrac{1}{3}=-\dfrac{17}{3}\)
hay \(x=-\dfrac{1}{2}:\dfrac{17}{3}=\dfrac{-3}{34}\)
a) 12/5 - 4/9 x 5/6 =
b) 5/6 x 9/20 : 2/3 =
c) 8/9 x 7/4 + 5/12 x 8/3 =
a)12/5-4/9x5/6=274/135
b)5/6x9/20:2/3=9/16
c)8/9x7/4+5/12x8/3=8/3
1/ \(\dfrac{x+4}{4}+\dfrac{3x-7}{5}=\dfrac{7x+2}{20}\)
2/ \(\dfrac{x}{6}+\dfrac{1-3x}{9}=\dfrac{-x+1}{12}\)
3/ \(\dfrac{x-3}{3}-\dfrac{x+2}{12}=\dfrac{2x-1}{4}\)
4/ \(\dfrac{x-2}{4}-\dfrac{2x+3}{3}=\dfrac{x+6}{12}\)
5/ \(\dfrac{2x-1}{12}-\dfrac{3-x}{18}=\dfrac{-1}{36}\)
1: Ta có: \(\dfrac{x+4}{4}+\dfrac{3x-7}{5}=\dfrac{7x+2}{20}\)
\(\Leftrightarrow5x+20+12x-28=7x+2\)
\(\Leftrightarrow17x-7x=2+8=10\)
hay x=1
2: Ta có: \(\dfrac{x}{6}+\dfrac{1-3x}{9}=\dfrac{-x+1}{12}\)
\(\Leftrightarrow\dfrac{6x}{36}+\dfrac{4\left(1-3x\right)}{36}=\dfrac{3\left(-x+1\right)}{36}\)
\(\Leftrightarrow6x+4-12x=-3x+3\)
\(\Leftrightarrow-6x+3x=3-4\)
hay \(x=\dfrac{1}{3}\)
3: Ta có: \(\dfrac{x-3}{3}-\dfrac{x+2}{12}=\dfrac{2x-1}{4}\)
\(\Leftrightarrow4x-12-x-2=6x-3\)
\(\Leftrightarrow3x-14-6x+3=0\)
\(\Leftrightarrow-3x=11\)
hay \(x=-\dfrac{11}{3}\)
4: Ta có: \(\dfrac{x-2}{4}-\dfrac{2x+3}{3}=\dfrac{x+6}{12}\)
\(\Leftrightarrow3x-6-8x-12=x+6\)
\(\Leftrightarrow-5x-x=6+18\)
hay x=-4
5: Ta có: \(\dfrac{2x-1}{12}-\dfrac{3-x}{18}=\dfrac{-1}{36}\)
\(\Leftrightarrow6x-3+2x-6=-1\)
\(\Leftrightarrow8x=8\)
hay x=1
tính nhanh:
7/12 + 4/9 + 1/3 + 5/12 + 2
6/5 x 3/8 + 5/8 x 6/5 - 4/5
Ta có thể đổi chỗ các phân số :
A)(7/12+5/12)+(4/9+1/3)+2=12/12+7/9+2=1+2+7/9=3+7/9=34/9
B)6/5*(3/8+5/8)-4/5=6/5*1-4/5=6/5-4/5=2/5