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1)
a)
\(\frac{-5}{6}.\frac{120}{25}< x< \frac{-7}{15}.\frac{9}{14}\)
\(\frac{-1}{1}.\frac{20}{5}< x< \frac{-1}{5}.\frac{3}{2}\)
\(\frac{-20}{5}< x< \frac{-3}{10}\)
\(\frac{-40}{10}< x< \frac{-3}{10}\)
\(\Rightarrow Z\in\left\{-4;-5;-6;-7;-8;-9;-10;...;-39\right\}\)
a)
5.(12-x)-20=30
⇒60-5x-20=30
⇒-5x=30+20-60
⇒-5x=-10
⇒x=2
b)(17x - 25 ) : 8 + 65 = 92
(17x - 25 ) : 8 + 65 = 81
17x - 25 = 16 x 8 = 128
17x = 128+25=153
x= 153:17 =9
c)
x=23
Giải thích các bước giải:
3x – 10 = 2x + 13
3x-2x=13+10
x=23
d)4(2x+7)-3(3x-2)=24
4.2x+4.7-3.3x+3.2=24
8x+28-9x+6=24
8x-9x=24-28-6=-10
=>(-1)x=-10
x=-10:(-1)
x=10
a. \(5\cdot\left(12-x\right)-20=30\Leftrightarrow5\left(12-x\right)=50\)
\(\Leftrightarrow12-x=50:5=10\)
\(\Leftrightarrow x=12-10=2\)
b. \(\left(17x-25\right):8+65=9^2\)
\(\Leftrightarrow\left(17x-25\right):8=81-65=16\)
\(\Leftrightarrow17x-25=16:8=2\)
\(\Leftrightarrow17x=2+25=27\Leftrightarrow x=\frac{27}{17}\)
c. \(3x-10=2x+13\)
\(\Leftrightarrow3x-2x=10+13\)
\(\Leftrightarrow x=23\)
d. \(4\cdot\left(2x+7\right)-3\cdot\left(3x-2\right)=24\)
\(\Leftrightarrow8x+28-9x+6=24\)
\(\Leftrightarrow34-x=24\Leftrightarrow x=10\)
a) \(3^x-2=5^2\)
\(\Rightarrow3^x-2=25\)
\(\Rightarrow3^x=27\)
\(\Rightarrow3^x=3^3\)
\(\Rightarrow x=3\)
b) \(\left(x+1\right)^2=36\)
\(\Rightarrow\left(x+1\right)^2=6^2\)
\(\Rightarrow x+1=6\)
\(\Rightarrow x=5\)
c) \(\left(2x-15\right)^5=\left(2x-15\right)^3\)
\(\Rightarrow\left(2x-15\right)^5:\left(2x-15\right)^3=1\)
\(\Rightarrow\left(2x-15\right)^2=1\)
\(\Rightarrow2x-15=1\)
\(\Rightarrow2x=16\)
\(\Rightarrow x=16:2=8\)
Chúc em học tốt nhé!
a) \(3^x-2=5^2\)
\(\Rightarrow3^x-2=25\)
\(\Rightarrow3^x=27\)
\(\Rightarrow3^x=3^3\)
\(\Rightarrow x=3\)
b) \(\left(x+1\right)^2=36\)
\(\Rightarrow\left(x+1\right)^2=6^2\)
\(\Rightarrow x+1=6\)
\(\Rightarrow x=5\)
c) \(\left(2x-15\right)^5=\left(2x-15\right)^3\)
\(\Rightarrow\left(2x-15\right)^5:\left(2x-15\right)^3=1\)
\(\Rightarrow\left(2x-15\right)^2=1\)
\(\Rightarrow\left(2x-15\right)^2=1^2\)
\(\Rightarrow2x-15=1\)
\(\Rightarrow2x=16\)
\(\Rightarrow x=8\)
Chúc em học tốt nhé!
\(2x-13=5-x\)
\(\Rightarrow2x+x=5+13\)
\(\Rightarrow3x=18\)
\(\Rightarrow x=6\)
\(-10⋮n-5\Rightarrow n-5\inƯ\left(-10\right)=\left\{\pm1;\pm2;\pm5;\pm10\right\}\)
\(\Rightarrow n\in\left\{6;4;7;3;10;0;15;-5\right\}\)
Vậy.............................
a)27^6:9^3=(3^3)^6:(3^2)^3=3^18:3^6=3^12
b)4^20:2^15=(2^2)^20:2^15=2^40:2^15=2^25
a) 27^6 : 9^3
= ( 3^3)^6 : ( 3^2)^3
= 3^18 : 3^6
= 3^12
b) 4^20 : 2^15
= ( 2^2)^20 : 2^15
= 2^40 : 2^15
= 2^25
d) 64^4 x 16^5 : 4^20
= (4^3)^4 x (4^2)^5 : 4^20
= 4^12 x 4^10 : 4^20
= 4^22 : 4^20
= 4^2
a) 10+2x=45:43
10+2x=42
10+2x=16
2x=16-10
2x=6
x=6:2
x=3
vậy x=3
b)130-(100+x)=25
100+x=130-25
100+x=105
x=105-100
x=5
vậy x=5
c)22.(x+32)-5=55
4.(x+9)=55+5
x+9=60:4
x+9=15
x=15-9
x=6
vậy x=9
d)72-7(13-x)=14
49-7(13-x)=14
7(13-x)=49-14
13-x=35:7
13-x=5
x=13-5
x=8
vậy x=8
\(\left(-3x+2\right)-\left(5-3x\right)=-3\)
\(\Rightarrow-3x+2-5+3x=-3\)
\(\Rightarrow-3x+3x=-3+5-2\)
\(\Rightarrow0x=0\Rightarrow x\in Z\)
\(3+x-\left(3x-1\right)=6-2x\)
\(\Rightarrow3+x-3x+1=6-2x\)
\(\Rightarrow x-3x+2x=6-1-3\)
\(\Rightarrow0x=2\left(loại\right)\)
\(\left(x-5\right)\left(3x+4\right)=0\)
\(\Leftrightarrow\orbr{\begin{cases}x-5=0\\3x+4=0\end{cases}\Leftrightarrow\orbr{\begin{cases}x=5\\x=-\frac{4}{3}\end{cases}}}\)
\(7x\left(2x-1\right)=0\)
\(\Leftrightarrow\orbr{\begin{cases}7x=0\\2x-1=0\end{cases}\Leftrightarrow\orbr{\begin{cases}x=0\\x=\frac{1}{2}\end{cases}}}\)
\(\left(3x-1\right)2x=0\)
\(\Leftrightarrow\orbr{\begin{cases}3x-1=0\\2x=0\end{cases}\Leftrightarrow\orbr{\begin{cases}x=\frac{1}{3}\\x=0\end{cases}}}\)
a,-2x -(x-17)=34-(-x+25)
-2x-x+17=34+x-25
-3x+17=9+x
-3x-x=9-17
-4x=-8
-->4x=8
x=8:4
x=2
Vậy x=2
b,17-(16x-37)=2x+43
17-16x+37=2x+43
20-16x=2x+43
-16x-2x=43-20
-18x=23
x=23:(-18)
x=23/-18
Mà x là số nguyên nên --> x thuộc tập rỗng
c,-2x-3.(x-17)=34-2(-x+25)
-2x-3x+51=34-2.(-x)-25
-5x+51=9-(-2).x
-5x+(-2).x=9-51
-7x=-42
7x=42
x=42:7
x=6
Vậy x=6
bài này không giải được đâu vì những số này đổi ra máy tính tính còn không được
1
a, 15 - ( 4 - x ) = 6
<=> 4 - x = 6 - 15
<=> 4 - x = -9
<=> x = -9 + 4
<=> x = -5
Mấy câu kia dễ tự làm :>
\(15-\left(4-x\right)=6\)
\(\Rightarrow4-x=9\)
\(\Rightarrow x=-5\)
\(a,3x-9=6\\ \Rightarrow3x=6+9\\ \Rightarrow3x=15\\ \Rightarrow x=15:3\\ \Rightarrow x=5\\ b,5-2x=3\\ \Rightarrow2x=5-3\\ \Rightarrow2x=2\\ \Rightarrow x=2:2\\ \Rightarrow x=1\\ d,43-\left(24-x\right)=20\\ \Rightarrow24-x=43-20\\ \Rightarrow24-x=23\\ \Rightarrow x=24-23\\ \Rightarrow x=1\)
Đề câu `c` sai
a: 3x-9=6
=>3x=9+6=15
=>\(x=\dfrac{15}{3}=5\)
b: 5-2x=3
=>2x=5-3=2
=>\(x=\dfrac{2}{2}=1\)
d: 43-(24-x)=20
=>24-x=43-20=23
=>x=24-23=1