1.tìm q biết:
a. 2 và 1/2 - (q - 1/2) = 3/5
b.1/3 x q - 1/5 x q =0,6
c. 3/5 - q : 1/2 = 1/7
Những câu hỏi liên quan
Tìm x biết:a) \(-\frac{2}{3}\left(x-\frac{1}{4}\right)=\frac{1}{3}\left(2x-1\right)\)
b)\(\frac{1}{5}.2^x+\frac{1}{3}.2^x^{+1}=\frac{1}{5}.2^7+\frac{1}{3}2^8\)
Gọi d là ƯCLN của 12n+1 và 30n+2
=> 12n+1 chia hết cho d. 30n+2 chia hết cho d
=> (12n+1) - (30n+2) chia hết cho d
=.> 5(12n+1) - 2(30n+2) chia hết cho d
=> 1 chia hết cho d
Ta có d C Ư(1) = [-1;1]
Vây phân số \(\frac{12n+1}{30n+2}\)là phân số tối giản
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Bài 3:cho
A=[0,8.7+(0,8)2].(1,25.7.4/5.1,25)+41,64
B=(1,09-0,29).4/5 phần (18,9-16,65)8/9
hỏi A gấp mấy lần B?
bài 4:tìm x thuộc Q biết:
a,-2/15-x-(-3/10)
b,3/4+1/4:x-2/5
b,2x.(x-1/4)-0
d,3/4.x-1/2-3/7
ai giúp mik vs
Bài 4:
b: Ta có: \(2x\left(x-\dfrac{1}{4}\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}x=0\\x=\dfrac{1}{4}\end{matrix}\right.\)
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1) cho 2a + 5b 7. Tìm GTLN của 3a2 + 2b22) cho 3a - 5b 8. chứng minh 7a2 +1 1b2gefrac{2464}{137}3) tìm GTLN của :a)A 3x + 3sqrt{3-x^2} với -sqrt{3}le xlesqrt{3}b) B (x + 3)(5 - 2x) với -3le xlefrac{5}{2}c)C (6x + 3)(5 - 2x) với frac{-1}{2}le xlefrac{5}{2}4) Tìm GTNN của y yfrac{x}{3}+frac{5}{2x-1}left(xfrac{1}{2}right)
Đọc tiếp
1) cho 2a + 5b = 7. Tìm GTLN của 3a2 + 2b2
2) cho 3a - 5b = 8. chứng minh 7a2 +1 1b2\(\ge\frac{2464}{137}\)
3) tìm GTLN của :
a)A = 3x + \(3\sqrt{3-x^2}\) với \(-\sqrt{3}\le x\le\sqrt{3}\)
b) B= (x + 3)(5 - 2x) với \(-3\le x\le\frac{5}{2}\)
c)C = (6x + 3)(5 - 2x) với \(\frac{-1}{2}\le x\le\frac{5}{2}\)
4) Tìm GTNN của y= \(y=\frac{x}{3}+\frac{5}{2x-1}\left(x>\frac{1}{2}\right)\)
Tìm x
a,-\(\frac{2}{3}\)(x-\(\frac{1}{4}\))=\(\frac{1}{3}\)(2x-1)
b,\(\frac{1}{5}\).2x+\(\frac{1}{3}\).2x+1=\(\frac{1}{5}.2^7+\frac{1}{7}.2^8\)
Tìm x biết :
1/dfrac{4}{3} + x dfrac{2}{15} 2/dfrac{1}{3}+dfrac{1}{2}: x -0,25 3/(dfrac{2x}{5}+2 ):(-4) -1dfrac{1}{2} 4/ x.( x + 1) 0 5/3dfrac{1}{2}-dfrac{1}{2}x dfrac{2}{3}
6/1dfrac{1}{2}+xdfrac{3}{2}-7 7/2x-1640+x 8/x:dfrac{5}{3}+dfrac{1}{3}dfrac{-2}{5} 9/dfrac{x}{4}dfrac{9}{x}
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Tìm x biết :
1/\(\dfrac{4}{3}\) + x = \(\dfrac{2}{15}\) 2/\(\dfrac{1}{3}+\dfrac{1}{2}:\) x = -0,25 3/(\(\dfrac{2x}{5}+2\) ):(-4) = -1\(\dfrac{1}{2}\) 4/ x.( x + 1) = 0 5/3\(\dfrac{1}{2}-\dfrac{1}{2}x\) = \(\dfrac{2}{3}\)
6/1\(\dfrac{1}{2}+x=\dfrac{3}{2}-7\) 7/\(2x-16=40+x\) 8/\(x:\dfrac{5}{3}+\dfrac{1}{3}=\dfrac{-2}{5}\) 9/\(\dfrac{x}{4}=\dfrac{9}{x}\)
9) \(\dfrac{x}{4}=\dfrac{9}{x}\)
Theo định nghĩa về hai phân số bằng nhau, ta có:
\(4\cdot9=x^2\\ 36=x^2\Rightarrow\left[{}\begin{matrix}x=6\\x=-6\end{matrix}\right.\)
8)
\(x:\dfrac{5}{3}+\dfrac{1}{3}=-\dfrac{2}{5}\\ x:\dfrac{5}{3}=-\dfrac{2}{5}+\dfrac{1}{3}\\ x:\dfrac{5}{3}=-\dfrac{1}{15}\\ x=\dfrac{1}{15}\cdot\dfrac{5}{3}\\ x=\dfrac{1}{9}\)
7)
\(2x-16=40+x\\ 2x-x=40+16\\ x\left(2-1\right)=56\\ x=56\)
6)
\(1\dfrac{1}{2}+x=\dfrac{3}{2}-7\\ \dfrac{3}{2}+x=\dfrac{3}{2}-7\\ \dfrac{3}{2}-\dfrac{3}{2}=-7-x\\ -7-x=0\\ x=-7-0\\ x=-7\)
5)
\(3\dfrac{1}{2}-\dfrac{1}{2}x=\dfrac{2}{3}\\ \dfrac{7}{2}-\dfrac{1}{2}x=\dfrac{2}{3}\\ \dfrac{1}{2}x=\dfrac{7}{2}-\dfrac{2}{3}\\ \dfrac{1}{2}x=\dfrac{17}{6}\\ x=\dfrac{17}{6}:\dfrac{1}{2}\\ x=\dfrac{17}{3}\)
4)
\(x\cdot\left(x+1\right)=0\Rightarrow\left[{}\begin{matrix}x=0\\x+1=0\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}x=0\\x=-1\end{matrix}\right.\)
3)
\(\left(\dfrac{2x}{5}+2\right):\left(-4\right)=-1\dfrac{1}{2}\\ \left(\dfrac{2x}{5}+2\right):\left(-4\right)=-\dfrac{3}{2}\\ \dfrac{2x}{5}+2=-\dfrac{3}{2}\cdot\left(-4\right)\\ \dfrac{2x}{5}+2=6\\ \dfrac{2x}{5}=6-2\\ \dfrac{2x}{5}=4\\ 2x=4\cdot5\\ 2x=20\\ x=20:2\\ x=10\)
2)
\(\dfrac{1}{3}+\dfrac{1}{2}:x=-0,25\\ \dfrac{1}{3}+\dfrac{1}{2}:x=-\dfrac{1}{4}\\ \dfrac{1}{2}:x=-\dfrac{1}{4}-\dfrac{1}{3}\\ \dfrac{1}{2}:x=-\dfrac{7}{12}\\ x=\dfrac{1}{2}:-\dfrac{7}{12}\\ x=-\dfrac{6}{7}\)
1)
\(\dfrac{4}{3}+x=\dfrac{2}{15}\\ x=\dfrac{2}{15}-\dfrac{4}{3}x=-\dfrac{6}{5}\)
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1.|x|frac{2}{3} 14.|x+3|frac{4}{5} 2.|x|frac{3}{5} 15.|x-7|frac{-5}{3}3.|x|frac{7}{4} 16.|x-7|frac{5}{3} 4.|x|-frac{-4}{7} 17.|x-frac{1}{2}|frac{1}{2}5.|x||frac{-3}{2}| 18.|x-frac{3}{2}|1frac{1}{3}6.|x|-frac{5}{-2} 19.|x-frac{5}{4}|-frac{1}{3}7.|x|5frac{1}{2} 20.|x+2|frac{1}{3}-frac{1}{5} 8.|x|frac{1}{5}-frac{1}{4} 21.|x-4|frac{1}{5}-left(frac{1}{2}-frac{5}{4}right)9.|x|-|frac{-4}{5}| 22.|x+3|frac{4}{5}-1frac{1}{2}+frac{7}{3}10.|x+1|fra...
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\(1.|x|=\frac{2}{3}\) \(14.|x+3|=\frac{4}{5}\)
\(2.|x|=\frac{3}{5}\) \(15.|x-7|=\frac{-5}{3}\)
\(3.|x|=\frac{7}{4}\) \(16.|x-7|=\frac{5}{3}\)
\(4.|x|=-\frac{-4}{7}\) \(17.|x-\frac{1}{2}|=\frac{1}{2}\)
\(5.|x|=|\frac{-3}{2}|\) \(18.|x-\frac{3}{2}|=1\frac{1}{3}\)
\(6.|x|=-\frac{5}{-2}\) \(19.|x-\frac{5}{4}|=-\frac{1}{3}\)
\(7.|x|=5\frac{1}{2}\) \(20.|x+2|=\frac{1}{3}-\frac{1}{5}\)
\(8.|x|=\frac{1}{5}-\frac{1}{4}\) \(21.|x-4|=\frac{1}{5}-\left(\frac{1}{2}-\frac{5}{4}\right)\)
\(9.|x|=-|\frac{-4}{5}|\) \(22.|x+3|=\frac{4}{5}-1\frac{1}{2}+\frac{7}{3}\)
\(10.|x+1|=\frac{1}{4}\)
\(11.|x-1|=\frac{2}{3}\)
\(12.|x+2|=\frac{1}{12}\)
\(13.|x-4|=\frac{1}{2}\)
bài 2 tìm xa,frac{-2}{3}.x+frac{1}{5}frac{3}{10}b,left|xright|-frac{3}{4}frac{5}{3}c,frac{2}{3}.x-frac{1}{2}frac{1}{10}d,frac{3}{5}+frac{4}{9}:xfrac{2}{3}e,left|x+75%right|2frac{1}{5}i,left(x+frac{1}{2}right).left(frac{2}{3}-2.xright)0k,frac{4}{7}.x-frac{2}{3}frac{1}{5}l,frac{2}{3}.x-frac{3}{2}.xfrac{5}{12}m,left|2.x-frac{1}{3}right|+frac{5}{6}1n,frac{1}{3}-frac{7}{8}.xfrac{1}{3}11,frac{x+2}{5}frac{7}{12}-1frac{1}{4}12,left(2frac{4}{5}.x-50right):frac{2}{3}5113,frac{2}{5}+frac{3}{5}.left(3.x-3,7...
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bài 2 tìm x
a,\(\frac{-2}{3}.x+\frac{1}{5}=\frac{3}{10}\)
b,\(\left|x\right|-\frac{3}{4}=\frac{5}{3}\)
c,\(\frac{2}{3}.x-\frac{1}{2}=\frac{1}{10}\)
d,\(\frac{3}{5}+\frac{4}{9}:x=\frac{2}{3}\)
e,\(\left|x+75\%\right|=2\frac{1}{5}\)
i,\(\left(x+\frac{1}{2}\right).\left(\frac{2}{3}-2.x\right)=0\)
k,\(\frac{4}{7}.x-\frac{2}{3}=\frac{1}{5}\)
l,\(\frac{2}{3}.x-\frac{3}{2}.x=\frac{5}{12}\)
m,\(\left|2.x-\frac{1}{3}\right|+\frac{5}{6}=1\)
n,\(\frac{1}{3}-\frac{7}{8}.x=\frac{1}{3}\)
11,\(\frac{x+2}{5}=\frac{7}{12}-1\frac{1}{4}\)
12,\(\left(2\frac{4}{5}.x-50\right):\frac{2}{3}=51\)
13,\(\frac{2}{5}+\frac{3}{5}.\left(3.x-3,7\right)=-\frac{53}{10}\)
14,\(\frac{7}{9}:\left(2+\frac{3}{4}.x\right)+\frac{5}{9}=\frac{23}{27}\)
ĐỀ: TÌM X
\(a,\frac{7}{5}:x+\frac{3}{2}=\frac{16}{3}\)
\(b,x:\frac{1}{5}+\frac{1}{7}=\frac{3}{5}.\frac{18}{21}\)
\(c,x-1\frac{1}{3}:2=\frac{5}{7}\)
\(d,x+2\frac{3}{5}.\frac{1}{6}=\frac{35}{36}\)
\(e,\left(x+\frac{3}{2}\right):2=\frac{7}{10}+\frac{1}{5}\)
ai trả lời được mik tik cho
a, 7/5 : x + 3/2 = 16/3
7/5 : x = 16/3 - 3/2
7/5 : x = 23/6
x = 7/5 : 23/6
x = 42/115
b, x : 1/5 + 1/7 = 3/5 . 18/21
x : 1/5 + 1/7 = 18/35
x : 1/5 = 18/35 - 1/7
x : 1/5 = 13/35
x = 13/35 . 1/5
x = 13/175
c, x - 1 và 1/3 : 2 = 5/7
x - 4/3 : 2 = 5/7
x - 4/3 = 5/7 . 2
x - 4/3 = 10/7
x = 10/7 + 4/3
x = 58/21
d, x + 2 và 3/5 . 1/6 = 35/36
x + 13/5 . 1/6 = 35/36
x + 13/5 = 35/36 : 1/6
x + 13/5 = 35/6
x = 35/6 - 13/5
x = 97/30
e, ( x + 3/2 ) : 2 = 7/10 + 1/5
( x + 3/2 ) : 2 = 9/10
x + 3/2 = 9/10 . 2
x + 3/2 = 9/5
x = 9/5 - 3/2
x = 3/10
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Tìm x :
1)\(\frac{x-1}{5}\)= \(\frac{x+2}{7}\)
2) \(\frac{x-1}{7}\)= \(\frac{5}{x+1}\)
3) \(\frac{x+1}{x-2}\)= \(\frac{x+2}{x+3}\)
1) \(\frac{x-1}{5}=\frac{x+2}{7}\)
\(\Rightarrow7x-7=5x+10\)
=> 7x - 5x = 10 + 7
2x = 17
x = 8,5
b) \(\frac{x-1}{7}=\frac{5}{x+1}\)
=> x2 - 1 = 35
x2 = 34
\(\Rightarrow x=\sqrt{34};x=-\sqrt{34}\)
c) \(\frac{x+1}{x-2}=\frac{x+2}{x+3}\)
=> x2 + 4x + 3 = x2 - 4
=> x2 - x2 + 4x + 3 = -4
4x + 3 = - 4
4x = -7
x = -7/4
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