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\(a,-12\left(x-5\right)+7\left(3-x\right)=5\)
\(-12x+60+21-7x=5\)
\(-12x-7x+81=5\)
\(-19x=5-81\)
\(-19x=-76\)
\(x=-76:\left(-19\right)\)
\(x=4\)
\(Vậyx=4\)
\(b,30\left(x+2\right)-6\left(x-5\right)-24x=100\)
\(30x+60-6x-30-24x=100\)
\(30x-6x-24x+60-30=100\)
\(0x+30=100\)
\(\Rightarrow Vôlý\)
Vậy không có giá trị nào của x thỏa mãn đề bài.
\(c,-5\left(x+\frac{1}{5}\right)-\frac{1}{2}\left(x-\frac{2}{3}\right)=\frac{3}{2}x-\frac{5}{6}\)
\(-5x-1-\frac{1}{2}x-\frac{1}{3}=\frac{3}{2}x-\frac{5}{6}\)
\(-5x-\frac{1}{2}x-1-\frac{1}{3}=\frac{3}{2}x-\frac{5}{6}\)
\(-\frac{11}{2}x-\frac{2}{3}=\frac{3}{2}x-\frac{5}{6}\)
\(-\frac{2}{3}+\frac{5}{6}=\frac{3}{2}x+\frac{11}{2}x\)
\(-\frac{4}{6}+\frac{5}{6}=\frac{14}{2}x\)
\(\frac{1}{6}=7x\)
\(x=\frac{1}{6}:7\)
\(x=\frac{1}{6}.\frac{1}{7}\)
\(x=\frac{1}{42}\)
\(Vậyx=\frac{1}{42}\)
\(d,-3\left(x-\frac{1}{2}\right)-5\left(x+\frac{3}{5}\right)=-x+\frac{1}{5}\)
\(-3x+\frac{3}{2}-5x-3=-x+\frac{1}{5}\)
\(-3x-5x+\frac{3}{2}-3=-x+\frac{1}{5}\)
\(-8x+\frac{3}{2}-\frac{6}{2}=-x+\frac{1}{5}\)
\(-8x-\frac{3}{2}=-x+\frac{1}{5}\)
\(-\frac{3}{2}-\frac{1}{5}=-x+8x\)
\(\frac{15}{10}-\frac{2}{10}=7x\)
\(7x=\frac{13}{10}\)
\(x=\frac{13}{10}:7\)
\(x=\frac{13}{10}.\frac{1}{7}\)
\(x=\frac{13}{70}\)
\(Vậyx=\frac{13}{70}\)
1) x - 2 = -6
x = -6 + 2
x = -4
2) -5 . x - ( -3 ) =13
-5 . x = 13 + ( -3 )
-5 . x = 10
x = 10 : ( -5 )
x = -2
\(\left(2x+\frac{3}{5}\right)^2-\frac{9}{25}=0\)
\(\Leftrightarrow\left(2x+\frac{3}{5}\right)^2=\frac{9}{25}\)
\(\Leftrightarrow\left(2x+\frac{3}{5}\right)^2=\left(\frac{3}{5}\right)^2\)
\(\Leftrightarrow\orbr{\begin{cases}2x+\frac{3}{5}=\frac{3}{5}\\2x+\frac{3}{5}=-\frac{3}{5}\end{cases}}\)
\(\Leftrightarrow\orbr{\begin{cases}2x=0\\2x=-\frac{6}{5}\end{cases}}\)
\(\Leftrightarrow\orbr{\begin{cases}x=0\\x=-\frac{3}{5}\end{cases}}\)
_Tần vũ_
\(3\left(3x-\frac{1}{2}\right)^3+\frac{1}{9}=0\)
\(\Leftrightarrow3\left(3x-\frac{1}{2}\right)^3=-\frac{1}{9}\)
\(\Leftrightarrow\left(3x-\frac{1}{2}\right)^3=-\frac{1}{27}\)
\(\Leftrightarrow\left(3x-\frac{1}{2}\right)^3=\left(-\frac{1}{3}\right)^3\)
\(\Leftrightarrow3x-\frac{1}{2}=\frac{-1}{3}\)
\(\Leftrightarrow3x=\frac{1}{6}\)
\(\Leftrightarrow x=\frac{1}{18}\)
_Tần Vũ_
e)x-43=(57-x)-50.
Suy ra x-43=57-x-50=57-50-x=7-x
Suy ra x-43+x=7. suy ra2x=7+43=50
Nên x=50:2=25
f)-(x-3+84)=(x+70-71)-5.
Suy ra -x+3-84=x-1-5=x-6
Suy ra -x-81=x-6. suy ra -x-81+6=x.suy ra-x-75=x
Suy ra -x-x=75 nên -2x=75 suy ra x=-75/2=-37.5
g)2(x-23)-(x-43)=96-115.
Suy ra 2x-46-x+43=-19,
suy ra 2x-x-46+43=-19,
suy ra x-3=-19
Nên x=-19+3=-16
h)2(x-12)+13=x+(-14)=x-14.
Suy ra 2x-24+13=x-14,
suy ra 2x-11=x-14,
suy ra 2x-11+14=x=2x+3,
suy ra x-2x=3 nên -x=3
vậy x=-3
1) 5.(3-x)+2.(x-7)=-14
15-5x+2x-14=-14
1-3x=-14
3x=15
X=5
2) 30.(x+2)-6.(x-5)-24x=100
30x+60-6x+30-24x=100
0X+90=100
0X=10 vô lí
=> ko có giá trị x thỏa mãn điều kiện
3) (3x-9)^2=36
3x-9=6
3x-9=-6
TH1:3x-9=6 TH2:3x-9=-6
3x=15 3x=3
X=5 x=1
Vậy….
4) (1-2x)^3=-27
(1-2x)3=(-3)3
1-2x=-3
2x=4
X=2
Vậy…
5) (x-3).(x-2)<0
=>x-3 và x-2 cùng dấu
TH1:x-3>0 TH2:x-3<0
x-2<0 x-2>0
=>X>3 =>x<3
X<2 x>2
=>x>3 =>x<2
Vậy 3<x<2
câu 6 chịuuuu
câu 5 hơi khó ko bt có đúng hay ko đâu :)))
3) \(\left(3x-9\right)^2=36\Leftrightarrow\orbr{\begin{cases}3x-9=6\\3x-9=-6\end{cases}\Leftrightarrow\orbr{\begin{cases}3x=15\\3x=3\end{cases}\Leftrightarrow}\orbr{\begin{cases}x=5\\x=1\end{cases}}}\)
4) \(\left(1-2x\right)^3=-27\)
<=> 1-2x=-3
<=> 3x=4
<=> \(x=\frac{4}{3}\)
5) (x-3)(x-2)<0
=> x-3 và x-2 trái dấu nhau
thấy x-3<x-2 => \(\hept{\begin{cases}x-3< 0\\x-2>0\end{cases}\Leftrightarrow\hept{\begin{cases}x< 3\\x>2\end{cases}\Leftrightarrow}2< x< 3}\)
6) làm tương tự
1) -5x - (-3) = 13
\(\Rightarrow-5x+3=13\)
\(\Rightarrow-5x=10\)
\(\Rightarrow x=-2\)
Vậy: \(x=-2\)
2) 15 - ( x - 7) = -21
\(\Rightarrow15-x+7=-21\)
\(\Rightarrow15+7-x=-21\)
\(\Rightarrow22-x=-21\)
\(\Rightarrow x=-22-21=-43\)
Vậy: \(x=-43\)
3) 45 - ( x - 9) = -35
\(\Rightarrow45-x+9=-35\)
\(\Rightarrow45+9-x=-35\)
\(\Rightarrow54-x=-35\)
\(\Rightarrow x=-54-35=-89\)
Vậy: \(x=-89\)
4)/x-2/=3\(\Rightarrow\)ta có 2 t/h:
t/h1: x-2=3\(\Rightarrow\)x=2+3=5
t/h2: x-2=-3\(\Rightarrow\)x=2+(-3)=-1
Vậy x=5 hoặc -1
1) (-1)3 + (-2)3 + (-3)3 - |x+5| = (5 - 6 -7)3
(-1) -8 - 27 - |x+5| = -512
|x+5| = 476
=> x + 5 = 476 hoặc x + 5 = -476
=> x = 472 => x = -481
Vậy....
2) [(x-3)2 - 9] . [(x-1)2-1]=0
( x - 3 - 3).(x - 3 + 3).(x - 1 - 1).(x - 1 +1) =0
( x - 6) . (x - 0) . (x - 2) . (x - 0) = 0
=> x - 6 = 0 hoặc x - 0 = 0 hoặc x - 2 = 0
=> x = 6 => x = 0 => x = 2
Vậy...