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B=\(6\frac{4}{9}-4\frac{4}{9}+3\frac{7}{11}\)
B=\(2+3\frac{7}{11}\)
B=\(5\frac{7}{11}\)
B = \(5\frac{7}{11}=\frac{62}{11}\)
C = 1
D = \(\frac{5}{2}=2\frac{1}{2}\)
a) 2x . 4 = 128
2x = 128 : 4
2x = 32
2x = 25
=> x = 5
b) 2x . 24 = 26
=> x + 4 = 6
x = 6 - 4
x = 2
c) 5x + x = 39 - 311 : 39
6x = 39 - 32
6x = 39 - 9
6x = 30
x = 30 : 6
x = 5
d) 9x - 1 = 81
9x - 1 = 92
=> x - 1 = 2
x = 2 + 1
x = 3
e) 6x = 521 : 519 + 3 . 22 - 70
6x = 52 + 3 . 4 - 1
6x = 25 + 12 - 1
6x = 37 - 1
6x = 36
x = 36 : 6
x = 6
Tìm \(x\) câu a:
\(\frac13.x\) + \(\frac25.\left(x+1\right)\) = 0
\(\frac{5}{15}x\) + \(\frac{6}{15}x\) + \(\frac25\) = 0
\(\frac{11}{15}x\) = - \(\frac25\)
\(x=-\frac25:\frac{11}{15}\)
\(x\) = - \(\frac25\times\frac{15}{11}\)
\(x\) = - \(\frac{6}{11}\)
Vậy \(x=-\frac{6}{11}\)
Tìm \(x\) câu b:
\(x\) x 25% = 0,5
\(x\times0,25\) = 0,5
\(x=0,5:0,25\)
\(x=2\)
Vậy \(x=2\)
Câu 1a:
1/3x + 2/5(x + 1) = 0
1/3x + 2/5x + 2/5 = 0
1/3x + 2/5x = - 2/5
x(1/3 + 2/5) = -2/5
x.(5/15 + 6/15) = -2/5
x.11/15 = - 2/5
x = - 2/5 : 11/15
x = - 6/11
Vậy x = -6/11
Câu b:
x . 25%. x = 0,5
x.x = 0,5 : 25%
x^2 = 2
x = - \(\sqrt2\); x = \(\sqrt2\)
Vậy x ∈ {- \(\sqrt2\); \(\sqrt2\) )
Câu 1a:
1/3x + 2/5(x + 1) = 0
1/3x + 2/5x + 2/5 = 0
1/3x + 2/5x = - 2/5
x(1/3 + 2/5) = -2/5
x.(5/15 + 6/15) = -2/5
x.11/15 = - 2/5
x = - 2/5 : 11/15
x = - 6/11
Vậy x = -6/11
Câu b:
x . 25%. x = 0,5
x.x = 0,5 : 25%
x^2 = 2
x = - \(\sqrt2\); x = \(\sqrt2\)
Vậy x ∈ {- \(\sqrt2\); \(\sqrt2\) )
a,\(4^n.2^n=512\)
\(\Rightarrow2^{2n}.2^n=512\Rightarrow2^{3n}=2^9\Rightarrow3n=9\Rightarrow n=3\)
b,\(3^n+3^{n+3}=252\)( sửa đề )
\(\Rightarrow3^n.\left(1+3^3\right)=252\Rightarrow3^n.28=252\Rightarrow3^n=9\Rightarrow n=2\)
c,\(2.3^{2x+2}=18\)
\(\Rightarrow3^{2n+2}=9\Rightarrow2n+2=2\Rightarrow n=0\)
d,\(x^2=2^3+3^2+4^3\)
\(\Rightarrow x^2=8+9+64\Rightarrow x^2=81\Rightarrow x^2=9^2=\left(-9\right)^2\Rightarrow x=9\)hoặc \(x=-9\)
e,\(x^5=x^9\)
\(\Rightarrow x^9-x^5=0\Rightarrow x^5.\left(x^4-1\right)=0\Rightarrow\hept{\begin{cases}x^5=0\\x^4-1=0\end{cases}\Rightarrow\hept{\begin{cases}x=0\\x=1\\x=-1\end{cases}}}\)
f,\(\left(x-4\right)^3=\left(x-4\right)^{10}\)
\(\Rightarrow\left(x-4\right)^{10}-\left(x-4\right)^3=0\Rightarrow\left(x-3\right)^3.\left[\left(x-3\right)^7-1\right]=0\)
\(\Rightarrow\hept{\begin{cases}\left(x-3\right)^3=0\\\left(x-3\right)^7=1\end{cases}\Rightarrow\hept{\begin{cases}x-3=0\\x-3=1\end{cases}\Rightarrow}\hept{\begin{cases}x=3\\x=4\end{cases}}}\)
dễ mà bạn đây là bài cơ bản lớp 6 dấy
câu a nhé bạn bạn nếu ko làm kiểu khó thì đổi về phaan số bình thường nà sau đó tính trong ngoặc trước rồi tính xoong bỏ dấu ngoặc nhưng ko đổi dấu né thế lad đc tương tự như các câu dưới
a)\(8\frac{2}{3}:2\frac{1}{6}-2\frac{27}{51}=\frac{26}{3}.\frac{6}{13}-\frac{43}{17}=4-\frac{43}{17}=\frac{25}{17}\)
b)\(\frac{27}{20}.\frac{15}{4}+\frac{19}{8}=\frac{119}{16}\)
c)\(\left(\frac{1}{12}+\frac{5}{6}\right)+\left(\frac{13}{35}+\frac{23}{35}\right)=\frac{11}{12}+\frac{36}{35}=\frac{817}{420}\)
d)\(\frac{24}{37}.\left(\frac{13}{18}+\frac{2}{9}+\frac{1}{18}\right)=\frac{24}{37}.1=\frac{24}{37}\)
320 : ( x - 1 ) = ( 53 - 52 ) : 4 + 15
<=> 320 : ( x - 1 ) = ( 125 - 25 ) : 4 + 15
<=> 320 : ( x - 1 ) = 100 : 4 + 15
<=> 320 : ( x - 1 ) = 40
<=> x - 1 = 8
<=> x = 9
240 : ( x - 5 ) = 22 . 52 - 20
<=> 240 : ( x - 5 ) = 4 . 25 - 20
<=> 240 : ( x - 5 ) = 80
<=> x - 5 = 3
<=> x = 8
70 : ( x - 3 ) = ( 34 - 1 ) : 4 - 16
<=> 70 : ( x - 3 ) = 80 : 4 - 16
<=> 70 : ( x - 3 ) = 4
<=> x - 3 = 35/2
<=> x = 41/2
a) 320: (x-1) = (53 - 52):4 + 15 b) 240: (x-5) = 22.52 - 20 c) 70:(x-3) = (34 - 1):4 - 16
320: (x-1) = (125- 25): 4 + 15 240: (x-5) = 4.25 - 20 70:(x-3) = (81-1): 4 - 16
320: (x-1) = 100:4 + 15 240: (x-5) = 100 - 20 70: (x-3) = 80: 4 - 16
320: (x-1) = 25 + 15 240: (x-5) = 80 70: (x-3) = 20 -16
320: (x-1) = 40 (x-5) = 240:80 70: (x-3) = 4
(x-1) = 320:40 (x-5) = 3 (x-3) = 70:4
(x-1) = 80 x = 5+3 (x-3) = 17,5
x = 80+1 x = 8 x = 17,5 : 3
x = 81 x = 5,83
\(\left(x-36\right):18=3\Leftrightarrow x-36=54\Leftrightarrow x=90\)
\(415-9\left(x+2\right)=2^2.5^2\Leftrightarrow415-9\left(x+2\right)=100\Leftrightarrow9\left(x+2\right)=315\Leftrightarrow x+2=35\Leftrightarrow x=33\)
\(5\left(4+6x\right)=290\Leftrightarrow4+6x=58\Leftrightarrow6x=54\Leftrightarrow x=9\)
Bài làm :
\(\left(x-36\right)\div18=3\)
\(\Leftrightarrow x-36=3\times18\)
\(\Leftrightarrow x-36=54\)
\(\Leftrightarrow x=54+36=90\)
\(415-9\times\left(x+2\right)=2^2\times5^2\)
\(\Leftrightarrow415-9\times x-9\times2=\left(2\times5\right)^2\)
\(\Leftrightarrow415-9\times x-18=10^2\)
\(\Leftrightarrow397-9\times x=100\)
\(\Leftrightarrow9\times x=397-100\)
\(\Leftrightarrow9\times x=297\)
\(\Leftrightarrow x=297\div9=33\).
\(5\times\left(4+6\times x\right)=290\)
\(\Leftrightarrow4+6\times x=290\div5\)
\(\Leftrightarrow4+6\times x=58\)
\(\Leftrightarrow6\times x=58-4\)
\(\Leftrightarrow6\times x=54\)
\(\Leftrightarrow x=54\div6=9\)
Chúc bạn học tốt !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
(x-36):18=3
(x-36)=3×18
(x-36)=54
x=54+36
x=90
vậy x=90
\(415-9×\left(x+2\right)=2^2×5^2\)
\(415-9×\left(x+2\right)=4×25\)
\(415-9×\left(x+2\right)=100\)
\(9×\left(x+2\right)=415-100\)
\(9×\left(x+2\right)=315\)
\(\left(x+2\right)=315:9\)
\(\left(x+2\right)=35\)
\(x=35-2\)
\(x=33\)
vậy \(x=33\)
5×(4+6×x)=290
(4+6×x)=290:5
(4+6×x)=58
6×x=58-4
6×x=54
x=54:6
x=9
vậy x=9
a ) \(\left(x-36\right)\div18=3\)
\(\Rightarrow x-36=18\cdot12\)
\(\Rightarrow x-36=216\)
\(\Rightarrow x=36+216\)
\(\Rightarrow x=252\)
b ) \(415-9\cdot\left(x+2\right)=2^2\cdot5^2\)
\(415-9\cdot\left(x+2\right)=4.25\)
\(415-9\cdot\left(x+2\right)=100\)
\(9\left(x+2\right)=415-100\)
\(9\left(x+2\right)=315\)
\(x+2=315\div9\)
\(x+2=35\)
\(x=35-2\)
\(x=33\)
c ) \(5\cdot\left(4+6\cdot x\right)=290\)
\(4+6x=290\div5\)
\(4+6x=58\)
\(6x=58-4\)
\(6x=54\)
\(x=54\div6\)
\(x=9\)