Tìm x trong các tỉ lệ thức sau:
a) \(\left(\frac{1}{3}.x\right):\frac{2}{3}=1\frac{3}{4}:\frac{2}{5}\)
b) 4,5 : 0,3 = 2,25 : (0,1 .x)
c) 8 : \(\left(\frac{1}{4}.x\right)=2:0,02\)
d) 3 : \(2\frac{1}{4}=\frac{3}{4}:\left(6.x\right)\)
Tìm x trong các tỉ lệ thức sau:
a) \(\left(\frac{1}{3}.x\right):\frac{2}{3}=1\frac{3}{4}:\frac{2}{5}\)
b) 4,5 : 0,3 = 2,25 : ( 0,1 .x)
c) \(8:\left(\frac{1}{4}.x\right)=2 :0,02\)
d) \(3:2\frac{1}{4}=\frac{3}{4}:\left(6.x\right)\)
1. tìm x trong các tỉ lệ thức sau:
a. \(\left(\frac{1}{3}.x\right):\frac{2}{3}=1\frac{3}{4}:2\)
b. 4,5:0,3 = 2,25:(0,1.x)
c. 8:\(\left(\frac{1}{4}.x\right)=2:0,02\)
c. \(3:2\frac{1}{4}=\frac{3}{4}:\left(6:x\right)\)
2. tìm hai số x,y,z biết rằng
\(\frac{x}{2}=\frac{y}{3},\frac{y}{4}=\frac{z}{5}\) và x+y-z=10
a)\(\left(\frac{1}{3}.x\right):\frac{2}{3}=1\frac{3}{4}:\frac{2}{5}\)
b)\(4,5:0,3=2,25:\left(0,1.x\right)\)
c)\(8:\left(\frac{1}{4}.x\right)=2:0,02\)
d) \(3:2\frac{1}{4}=\frac{2}{3}:\left(6.x\right)\)
tìm x biết:
a,\(\left(\frac{1}{3}.x\right):\frac{2}{3}=1\frac{2}{3}:\frac{2}{5}\)
b,\(4,5:0,3=2,25:\left(0,1.x\right)\)
c,\(8:\left(\frac{1}{4}.x\right)=2:0,02\)
d,\(3:2\frac{1}{4}=\frac{3}{4}:\left(6.x\right)\)
e,\(3,8:\left(2.x\right)=\frac{1}{4}:2\frac{2}{3}\)
f,\(\left(0,25.x\right):3=\frac{5}{6}:0,125\)
g,\(1\frac{1}{3}:0,8=\frac{2}{3}:\left(0.1.x\right)\)
làm 1 bài mẫu nha
a) \(\left(\frac{1}{3}.x\right):\frac{2}{3}=\frac{25}{6}\)
\(\Rightarrow\frac{1}{3}x=\frac{25}{9}\)
\(\Rightarrow x=\frac{25}{9}:\frac{1}{3}\)
\(\Rightarrow x=\frac{25}{3}\)
các bài sau dễ lắm
a) \(\left(\frac{1}{3}x\right):\frac{2}{3}=1\frac{2}{3}:\frac{2}{5}\)
\(\Rightarrow\frac{1}{3}x:\frac{2}{3}=\frac{25}{6}\)
\(\Rightarrow\frac{1}{3}x=\frac{5}{3}\)
\(\Rightarrow x=\frac{5}{3}:\frac{1}{3}\)
\(\Rightarrow x=5\)
a) \(\left(\frac{1}{3}\cdot x\right):\frac{2}{3}=1\frac{2}{3}:\frac{2}{5}\)
\(\left(\frac{1}{3}\cdot x\right):\frac{2}{3}=\frac{25}{6}\)
\(\frac{1}{3}x=\frac{25}{6}\cdot\frac{2}{3}\)
\(\frac{1}{3}x=\frac{25}{9}\)
\(x=\frac{25}{9}:\frac{1}{3}\)
\(x=\frac{25}{3}\)
b) \(4,5:0,3=2,25:\left(0,1x\right)\)
\(15=2,25:\left(0,1x\right)\)
\(2,25:15=0,1x\)
\(0,15=0,1x\)
\(0,15:0,1=x\)
\(1,5=x\)
c) \(8:\left(\frac{1}{4}\cdot x\right)=2:0,02\)
\(8:\left(\frac{1}{4}\cdot x\right)=100\)
\(\frac{1}{4}\cdot x=8:100\)
\(\frac{1}{4}\cdot x=0,08\)
\(x=0,08:\frac{1}{4}\)
\(x=0,32\)
d) \(3:2\frac{1}{4}=\frac{3}{4}:\left(6\cdot x\right)\)
\(\frac{4}{3}=\frac{3}{4}:\left(6\cdot x\right)\)
\(\frac{3}{4}:\frac{4}{3}=6\cdot x\)
\(\frac{9}{16}=6\cdot x\)
\(\frac{9}{16}:6=x\)
\(\frac{3}{32}=x\)
e) \(3,8:\left(2\cdot x\right)=\frac{1}{4}:2\frac{2}{3}\)
\(3,8:\left(2\cdot x\right)=\frac{3}{32}\)
\(2\cdot x=3,8:\frac{3}{32}\)
\(2\cdot x=\frac{608}{15}\)
\(x=\frac{608}{15}:2\)
\(x=\frac{304}{15}\)
f) \(\left(0,25\cdot x\right):3=\frac{5}{6}:0,125\)
\(\left(0,25\cdot x\right):3=\frac{20}{3}\)
\(0,25\cdot x=\frac{20}{3}\cdot3\)
\(0,25\cdot x=20\)
\(x=20:0,25\)
\(x=80\)
g) \(1\frac{1}{3}:0,8=\frac{2}{3}:\left(0,1\cdot x\right)\)
\(\frac{5}{3}=\frac{2}{3}:\left(0,1\cdot x\right)\)
\(\frac{2}{3}:\frac{5}{3}=0,1\cdot x\)
\(\frac{2}{5}=0,1x\)
\(\frac{2}{5}:0,1=x\)
\(4=x\)
(Nhớ thử lại kết quả nhé)
Tim x trong cac ti le thuc sau
a) \(\left(\frac{1}{3}.x\right):\frac{2}{3}=1\frac{3}{4}:\frac{2}{5}\)
b)\(4,5:0,3=2,25:\left(0,1.x\right)\)
c)\(8:\left(\frac{1}{4}.x\right)=2:0.02\)
d)\(3:2\frac{1}{4}=\frac{3}{4}:\left(6.x\right)\)
a)\(\left(\frac{1}{3}.x\right):\frac{2}{3}=\frac{7}{4}.\frac{5}{2}\)
\(\left(\frac{1}{3}.x\right):\frac{2}{3}=\frac{35}{8}\)
\(\frac{1}{3}.x=\frac{35}{8}.\frac{2}{3}\)
\(\frac{1}{3}.x=\frac{35}{12}\)
\(x=\frac{35}{12}:\frac{1}{3}\)
\(x=\frac{35}{12}.\frac{3}{1}\)
\(x=\frac{35}{4}\)
b)\(\frac{4,5}{0,3}=\frac{2,25}{0,1.x}\)
\(4,5.\left(0,1.x\right)=2,25.0,3\)
\(4,5.\left(0,1.x\right)=0,675\)
\(0,1.x=0,675:4,5\)
\(0,1.x=0,15\)
\(x=0,15:0,1\)
\(x=1.5\)
c)\(\frac{8}{\frac{1}{4}.x}=\frac{2}{0,02}\)
\(\left(\frac{1}{4}.x\right).2=8.0,02\)
\(\left(\frac{1}{4}.x\right).2=0,16\)
\(\frac{1}{4}.x=0,16:2\)
\(\frac{1}{4}.x=0,08\)
\(x=0,08:\frac{1}{4}\)
\(x=0,32\)
d)\(\frac{3}{\frac{9}{4}}=\frac{\frac{3}{4}}{6.x}\)
\(3.\left(6.x\right)=\frac{3}{4}.\frac{9}{4}\)
\(3.\left(6.x\right)=\frac{27}{16}\)
\(6.x=\frac{27}{16}:3\)
\(6.x=\frac{9}{16}\)
\(x=\frac{9}{16}:6\)
\(x=\frac{3}{32}\)
HỌC TỐT ^^
tìm x trong các tỉ lệ thữ sau:
a) \(\left(\frac{1}{3}\times x\right)\) : \(\frac{2}{3}=1\frac{3}{4}\) : \(\frac{2}{5}\)
b) 4,5 : 0,3 = 2,25 : ( 0,1 . x )
c) 8 : \(\left(\frac{1}{4}\times x\right)\) = 2 : 0,02
d) 3 : \(2\frac{1}{4}\) = \(\frac{3}{4}\) : ( 6 . x )
a. => (1/3.x):2/3=7/4:2/5
=> 1/3.x=(7/4.2/3):2/5
=> 1/3.x=7/6.5/2
=> 1/3.x=35/12
=> x=35/12:1/3
=> x=35/12.3
=> x=35/4
b. => 4,5.(0,1.x)=0,3.2,25
=> 4,5.(0,1.x)=0,675
=> 0,1.x=0,675:4,5
=> 0,1.x=0,15
=> x=0,15:0,1
=> x=1,5
c. => 2.(1/4.x)=8.0,02
=> 1/2.x=0,16
=> x=0,16:1/2
=> x=0,16.2
=> x=0,32
d. => 3:9/4=3/4:(6.x)
=> 3.(6.x)=9/4.3/4
=> 18.x=27/16
=> x=27/16:18
=> x=27/16.1/18
=> x=3/32
a) ( 1/3 . x ) : 2/3 = 7/4 : 2/5
1/3 . x : 2/3 = 35/8
1/3 . x = 35/8 . 2/3
1/3 . x = 35/12
x = 35/12 : 1/3
x = 35/4
1) Tìm x
a) 4,5 : 0,3 = 2,25 : (0,1 . x)
b) 8 : \(\left(\frac{1}{4}.x\right)\) = 2 : 0,02
c) 3 : \(2\frac{1}{4}\) = \(\frac{3}{4}\) : (6 . x)
a)4,5:0,3=2,25:(0,1.x)
2,25:(0,1.x)=15
0,1.x=0,15
x=0,15:0,1
x=1,5
Vậy x=1,5
b)8:\(\left(\frac{1}{4}.x\right)\)=2:0,02
8:\(\left(\frac{1}{4}.x\right)\)=100
\(\left(\frac{1}{4}.x\right)\)=\(\frac{8}{100}\)
x=\(\frac{8}{100}\):\(\frac{1}{4}\)
x=\(\frac{8}{25}\)
Vậy x=\(\frac{8}{25}\)
c)\(3:2\frac{1}{4}=\frac{3}{4}:\left(6.x\right)\)
\(\frac{3}{4}:\left(6.x\right)=\frac{4}{3}\)
6.x=\(\frac{3}{4}:\frac{4}{3}\)
6.x=\(\frac{9}{16}\)
x=\(\frac{9}{16}\):6
x=\(\frac{3}{32}\)
Vậy x=\(\frac{3}{32}\)
a.
\(4,5\div0,3=2,25\div\left(0,1\times x\right)\)
\(2,25\div\left(0,1\times x\right)=15\)
\(0,1\times x=\frac{2,25}{15}\)
\(0,1\times x=0,15\)
\(x=\frac{0,15}{0,1}\)
\(x=1,5\)
b.
\(8\div\left(\frac{1}{4}\times x\right)=2\div0,02\)
\(8\div\left(\frac{1}{4}\times x\right)=100\)
\(\frac{1}{4}\times x=\frac{8}{100}\)
\(\frac{1}{4}\times x=\frac{2}{25}\)
\(x=\frac{2}{25}\div\frac{1}{4}\)
\(x=\frac{2}{25}\times4\)
\(x=\frac{8}{25}\)
c.
\(3\div2^1_4=\frac{3}{4}\div\left(6\times x\right)\)
\(\frac{3}{4}\div\left(6\times x\right)=3\div2,25\)
\(\frac{3}{4}\div\left(6\times x\right)=\frac{4}{3}\)
\(6\times x=\frac{3}{4}\div\frac{4}{3}\)
\(6\times x=\frac{3}{4}\times\frac{3}{4}\)
\(6\times x=\frac{9}{16}\)
\(x=\frac{9}{16}\div6\)
\(x=\frac{9}{16}\times\frac{1}{6}\)
\(x=\frac{3}{32}\)
Tìm \(x\) trong các tỉ lệ thức sau :
a) \(\left(\dfrac{1}{3}.x\right):\dfrac{2}{3}=1\dfrac{3}{4}:\dfrac{2}{5}\)
b) \(4,5:0,3=2,25:\left(0,1.x\right)\)
c) \(8:\left(\dfrac{1}{4}.x\right)=2:0,02\)
d) \(3:2\dfrac{1}{4}=\dfrac{3}{4}:\left(6.x\right)\)
a)
b) 4,5 : 0,3 = 2,25 : ( 0,1.x) => 0,1.x =
c)
d)
Bạn hãy chỉ giúp mình cách viết phân số và hỗn số trên máy tính. Mình cảm ơn bạn nhiều lắm!^ - ^
1.Tính:
\(a,A=\sqrt{12\frac{1}{4}}.\left(\frac{-2}{7}\right)^2-\left[2,\left(4\right).2\frac{5}{11}\right]:\left(\frac{-42}{5}\right)\)
\(B=\frac{1}{3}+\frac{2}{3^2}+\frac{3}{3^3}+\frac{4}{3^4}+...+\frac{2016}{3^{2016}}\)
2. Tìm x,y,z biết:
a) \(\left|x+1\right|+\left|x+2\right|+\left|x+4\right|+\left|x+5\right|-6x=0\)
b) \(\sqrt{\left(x+\sqrt{5}\right)^2}+\sqrt{\left(y+\sqrt{3}\right)^2}+\left|x-y-z\right|=0\)
c) \(\frac{x-2}{2}=\frac{y-3}{3}=\frac{z-3}{4}\) và x-2y+3z=14.
d) \(5^x+5^{x+1}+5^{x+2}=3875\).
3. a) Cho bốn số a,b,c,d>0 thỏa mãn: \(\frac{1}{c}=\frac{ }{1}2.\left(\frac{1}{b}+\frac{1}{a}\right)\)và b là trung bình cộng của a và c. Chứng minh rằng bốn số đó lập nên một tỉ lệ thức.
b) Cho tỉ lệ thức: \(\frac{2a+13b}{3a-7b}=\frac{2c+13d}{3c-7d}\) (với a,b,c,d khác 0)
Chứng minh rằng: \(\frac{a}{b}=\frac{c}{d}\)
Bài 2:
a) \(\left|x+1\right|+\left|x+2\right|+\left|x+4\right|+\left|x+5\right|-6x=0\)
\(\Rightarrow\left|x+1\right|+\left|x+2\right|+\left|x+4\right|+\left|x+5\right|=6x\)
Ta có: \(\left|x+1\right|\ge0;\left|x+2\right|\ge0;\left|x+4\right|\ge0;\left|x+5\right|\ge0\)
\(\Rightarrow\left|x+1\right|+\left|x+2\right|+\left|x+4\right|+\left|x+5\right|\ge0\)
\(\Rightarrow6x\ge0\)
\(\Rightarrow x\ge0\)
\(\Rightarrow\left|x+1\right|+\left|x+2\right|+\left|x+4\right|+\left|x+5\right|=x+1+x+2+x+4+x+5=6x\)
\(\Rightarrow4x+12=6x\)
\(\Rightarrow2x=12\)
\(\Rightarrow x=6\)
Vậy x = 6
b) Giải:
Áp dụng tính chất dãy tỉ số bằng nhau ta có:
\(\frac{x-2}{2}=\frac{y-3}{3}=\frac{z-3}{4}=\frac{2y-6}{6}=\frac{3z-9}{12}=\frac{x-2-2y+6+3z-9}{2-6+12}=\frac{\left(x-2y+3z\right)-\left(2-6+9\right)}{8}\)
\(=\frac{14-5}{8}=\frac{9}{8}\)
+) \(\frac{x-2}{2}=\frac{9}{8}\Rightarrow x-2=\frac{9}{4}\Rightarrow x=\frac{17}{4}\)
+) \(\frac{y-3}{3}=\frac{9}{8}\Rightarrow y-3=\frac{27}{8}\Rightarrow y=\frac{51}{8}\)
+) \(\frac{z-3}{4}=\frac{9}{8}\Rightarrow z-3=\frac{9}{2}\Rightarrow z=\frac{15}{2}\)
Vậy ...
c) \(5^x+5^{x+1}+5^{x+2}=3875\)
\(\Rightarrow5^x+5^x.5+5^x.5^2=3875\)
\(\Rightarrow5^x.\left(1+5+5^2\right)=3875\)
\(\Rightarrow5^x.31=3875\)
\(\Rightarrow5^x=125\)
\(\Rightarrow5^x=5^3\)
\(\Rightarrow x=3\)
Vậy x = 3