(x + 1/7) ^3 - 1 =1,26 : 0,02
Tìm x:
a) \(\dfrac{1}{2}+\dfrac{2}{3}x=\dfrac{1}{4}\)
b) \(2\dfrac{2}{3}:x=1\dfrac{7}{9}:0,02\)
c) \(x^x-x+1=1\)
d) \(5-\left|3x-1\right|=3\)
a) \(\dfrac{1}{2}+\dfrac{2}{3}x=\dfrac{1}{4}\\ \Rightarrow\dfrac{2}{3}x=-\dfrac{1}{4}\\ \Rightarrow x=-\dfrac{3}{8}\)
b) \(2\dfrac{2}{3}:x=1\dfrac{7}{9}:0,02\\ \Rightarrow2\dfrac{2}{3}:x=\dfrac{800}{9}\\ \Rightarrow x=\dfrac{3}{100}\)
c) \(x^x-x+1=1\\ \Rightarrow x^x-x=0\\ \Rightarrow x^x=x\\ \Rightarrow x=1\)
d) \(5-\left|3x-1\right|=3\\ \Rightarrow\left|3x-1\right|=2\\ \Rightarrow\left[{}\begin{matrix}3x-1=-2\\3x-1=2\end{matrix}\right.\\ \Rightarrow\left[{}\begin{matrix}x=-\dfrac{1}{3}\\x=1\end{matrix}\right.\)
a, x=-3/8
b,x=3/100
c,x=0
d,x=-1/3 hoặc x=1
2/2/3:x=1/7/9:0,02
-3/5:3/14+0,5.x=12
2^2x+1=2^3.2^4
|3-x|+1/2=5
\(2\frac{2}{3}:x=1\frac{8}{9}:0,02\)
\(\frac{8}{3}:x=\frac{17}{9}:\frac{1}{50}\)
\(\frac{8}{3}:x=\frac{17}{9}.50\)
\(\frac{8}{3}:x=\frac{850}{9}\)
\(x=\frac{8}{3}:\frac{850}{9}\)
\(x=\frac{8}{3}x\frac{9}{850}\)
\(x=\frac{12}{425}\)
Vậy \(x=\frac{12}{425}\)
\(-\frac{3}{5}:\frac{3}{14}+0,5.x=12\)
\(-\frac{3}{5}:\frac{3}{14}+\frac{1}{2}.x=12\)\(-\frac{3}{5}x\frac{14}{3}+\frac{1}{2}.x=12\)\(-\frac{14}{5}+\frac{1}{2}.x=12\)\(\frac{1}{2}.x=12-\left(-\frac{14}{5}\right)\)\(\frac{1}{2}.x=12+\frac{14}{5}\)\(\frac{1}{2}.x=\frac{60}{5}+\frac{14}{5}\)\(\frac{1}{2}.x=\frac{74}{5}\) \(x=\frac{74}{5}:\frac{1}{2}\) \(x=\frac{74}{5}x2\) \(x=\frac{158}{5}\) Vậy \(x=\frac{158}{5}\)Tìm x trong các tỉ lệ thức sau:
a, ( 1/3 . x ) : 2/3 = 7/4 : 2/5
b, 4,5 : 0,3 = 2,25 : ( 0,1 . x )
c, 8 : ( 1/4 . x ) = 2 : 0,02
d, 3 : 9/4 = 3/4 : ( 6 . x )
a) \(\left(\frac{1}{3}.x\right):\frac{2}{3}=\frac{7}{4}:\frac{2}{5}\)
\(\left(\frac{1}{3}.x\right):\frac{2}{3}=\frac{35}{8}\)
\(\Rightarrow\frac{1}{3}.x=\frac{35}{8}.\frac{2}{3}\)
\(\Rightarrow\frac{1}{3}.x=\frac{35}{12}\)
\(\Rightarrow x=\frac{35}{12}:\frac{1}{3}\)
\(\Rightarrow x=\frac{35}{4}\)
Vậy \(x=\frac{35}{4}\)
\(a.\left(\frac{1}{3}.x\right):\frac{2}{3}=\frac{7}{4}:\frac{2}{5}\)
\(\left(\frac{1}{3}.x\right):\frac{2}{3}=\frac{35}{8}\)
\(\left(\frac{1}{3}.x\right)=\frac{35}{8}.\frac{2}{3}\)
\(\left(\frac{1}{3}.x\right)=\frac{35}{12}\)
\(x=\frac{35}{12}:\frac{1}{3}\)
\(x=\frac{35}{4}\)
\(b.4,5:0,3=2,25:\left(0,1.x\right)\)
\(\Rightarrow2,25:\left(0,1.x\right)=4,5:0,3\)
\(2,25:\left(0,1.x\right)=15\)
\(2,25:\left(0,1.x\right)=2,25:15\)
\(\left(0,1.x\right)=0,15\)
\(x=0,15:0,1\)
\(x=1,5\)
\(c.8:\left(\frac{1}{4}.x\right)=2:0,02\)
\(8:\left(\frac{1}{4}.x\right)=100\)
\(\left(\frac{1}{4}.x\right)=8:100\)
\(\left(\frac{1}{4}.x\right)=\frac{2}{25}\)
\(x=\frac{2}{25}:\frac{1}{4}\)
\(x=\frac{8}{25}\)
\(d.3:\frac{9}{4}=\frac{3}{4}:\left(6.x\right)\)
\(\Rightarrow\frac{3}{4}:\left(6.x\right)=3:\frac{9}{4}\)
\(\frac{3}{4}:\left(6.x\right)=\frac{4}{3}\)
\(\left(6.x\right)=\frac{3}{4}:\frac{4}{3}\)
\(\left(6.x\right)=\frac{9}{16}\)
\(x=\frac{9}{16}:6\)
\(x=\frac{3}{32}\)
^...^ ^_^
Câu 17.Tìm X: X : 7 = 21,7
a. 3 b. 3,1 c. 3,01 d. Một kết quả khác
Câu 18.Kết quả của dãy tính: 4 x 2,5 x 12,6 là:
a. 12,6 b. 1,26 c . 126 d. Một kết quả khác
Tính bằng hai cách:
a) \(\dfrac{7}{11}:\dfrac{3}{5}+\dfrac{4}{11}:\dfrac{3}{5}\); b) \(\left(6,24+1,26\right):0,75\).
a) \(\dfrac{3}{5}:\left(\dfrac{7}{11}+\dfrac{4}{11}\right)=\dfrac{3}{5}.1=\dfrac{3}{5}\)
c2: \(\dfrac{7}{11}:\dfrac{3}{5}+\dfrac{4}{11}:\dfrac{3}{5}=\dfrac{7}{11}.\dfrac{5}{3}+\dfrac{4}{11}.\dfrac{5}{3}=\dfrac{3}{5}\)
a)
C1: \(\dfrac{7}{11}:\dfrac{3}{5}+\dfrac{4}{11}:\dfrac{3}{5}=\left(\dfrac{7}{11}+\dfrac{4}{11}\right):\dfrac{3}{5}=1:\dfrac{3}{5}=\dfrac{5}{3}\)
Tính bằng hai cách
A) 7/11:3/5+4/11:3/5
B) (6,24+1,26):0,75
tính = 2 cách
a) 7/11 : 3/5 : 4/11 : 3/5= ?
b) (6,24 + 1,26) : 0,75= ?
Cách 1
A)(7/11*4/11)*5/3=1*5/3
Cách 2 (7/11*4/11):3/5=1:3/5=5/3
Cách 1
B)7,5:0,75=10
Cách 2
6,24:0,75+1,26:0,75=8,32+1,68
Lời giải bài toán 4/164
tìm x
a , ( 1/3 .x) : 2/3 = 1/3/4 : 2/5
b , 4,5 : 0,3 = 2,25 : ( 0,1 .x)
c , 8 : ( 1/4 .x ) = 2: 0,02
d , 3 : 2/1/4 = 3/4 : ( 6 .x )
a.=> \(\frac{\left(\frac{1}{3}\right).x}{\frac{2}{3}}=\frac{\frac{7}{4}}{\frac{2}{5}}\)
=> \(\frac{1}{3}.x=\frac{7}{4}.\frac{2}{3}:\frac{2}{5}\)
=>\(\frac{1}{3}.x=\frac{35}{12}\)
=> x\(=\frac{35}{12}:\frac{1}{3}\)
Vậy x=\(\frac{35}{4}\).
b. => \(\frac{4,5}{0,3}=\frac{2,25}{0,1.x}\)
=>\(0,1.x=\frac{2,25.0,3}{4,5}\)
=>\(0,1.x=0,15\)
=>\(x=0,15:0,1\)
Vậy x=1,5
c. =>\(\frac{8}{\frac{1}{4}.x}=\frac{2}{0,02}\)
=>\(\frac{1}{4}.x=\frac{8.0,02}{2}\)
=>\(\frac{1}{4}.x=0,08\)
=>\(x=0,08:\frac{1}{4}\)
Vậy x=0,32.
d. =>\(\frac{3}{\frac{9}{4}}=\frac{\frac{3}{4}}{6.x}\)
=>\(3.6x=\frac{9}{4}.\frac{3}{4}\)
=>\(18x=\frac{27}{16}\)
=>\(x=\frac{27}{16}:18\)
Vậy x=\(\frac{3}{32}\)