tìm x, biết
(x-2)^8=(x-2)^6
Tìm x biết:
2/(x+2)(x+4)+ 4/(x+4)(x+8)+6/(x+8)(x+14)=x/(x+2)(x+14)
a) Tìm x thuộc Z biết: -2(x+6)+6(x-10)=8
b) Tìm các số nguyên x,y biết (x+2)(y-3)=5
\(\text{(x+2)(y-3)=5 }\)
\(\Rightarrow\)x+2;y-3\(\in\)Ư(5)
Mà Ư(5)={1;5;-1;-5}
Có bảng:
Th1:
x+2=1;y-3=6
=>x=-3
y=9
Tương tự 3 trường hợp còn lại
A) -2(x+6)+6(x-10) = 8
= (-2x)+(-2.6) + 6x-6.10 =8
= (-2x+6x)-(12+60) = 8
= 4x - 72 = 8
=4x = 80
= x =20
b) x là : -3 ; -1
y là : -2 ; 8
còn cách giải bài b thì bn kia giải rồi nhé
a.-2(x+6)+6(x-10)=8
-2x+6+6x-10=8
-2x+6x+6-10=8
4x+6-10=8
4x+6=8+10
4x+6=18
4x=18-6
4x=12
x=12:4
x=3
b.(x+2)(y-3)=5
=>(x+2)(y-3)thuộc Ư(5)={1;-1;5;-5}
=>TH1:x+2=1 hoặc x+2=5 và y-3=1 hoặc y-3=5
x=1-2 x=5-2 y=1+3 y=5+3
x=-1 x=3 y=4 y=8
TH2:x+2=-1 hoặc x+2=-5 và y-3=-1 hoặc y-3=-5
x=-1-2 x=-5-2 y=-1+3 y=-5+3
x=-3 x=-7 y=2 y=-2
Tìm x biết: |x-2| + |x-4| + |x-6| + |x-8| = 8
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Dạng giống phần a nha bạn
tìm x biết
1) x=-1/2 + 3/4 2) x - 1/5 = 2/11 3) x - 5/6 = 16/42 + -8/56
4) x/5 = 5/6 + -19/30 5) |x| - 1/4 = 6/18 6)x = -1/2 +3/4
7) x/15 = 3/5 + -2/3 8)11/8 + 13/6 = 85/x 9) x - 7/8 = 13/12
10) x - -6/15 = 4/27 11) -\(\dfrac{-6}{12}\)+ x = 9/48 12) x - 4/6 = 5/25 + -7/15
1: x=3/4-1/2=3/4-2/4=1/4
2: x-1/5=2/11
=>x=2/11+1/5=21/55
3: x-5/6=16/42-8/56
=>x-5/6=8/21-4/28=5/21
=>x=5/21+5/6=15/14
4: x/5=5/6-19/30
=>x/5=25/30-19/30=6/30=1/5
=>x=1
5: =>|x|=1/3+1/4=7/12
=>x=7/12 hoặc x=-7/12
6: x=-1/2+3/4
=>x=3/4-1/2=1/4
11: x-(-6/12)=9/48
=>x+1/2=3/16
=>x=3/16-1/2=-5/16
1)x= 1/4
2)x= 2/11+ 1/5
x= 21/55
3)x - 5/6 = 5/21
x = 5/21+5/6
x = 15/14
4)x/5 = 5/6 + -19/30
x:5 = 1/5
x = 1/5.5
x = 1
5) |x| - 1/4 = 6/18
|x| = 6/18 - 1/4
|x| =7/12
⇒x= 7/12 hoặc -7/12
6)x = -1/2 +3/4
x= 1/4
7) x/15 = 3/5 + -2/3
x:15 = -1/15
x = -1/15. 15
x = -1
8)11/8 + 13/6 = 85/x
85/24 = 85/x
⇒ x = 24
9) x - 7/8 = 13/12
x = 13/12 + 7/8
x = 47/24
10)x - -6/15 = 4/27
x = 4/27 + (-6/15)
x = -34/135
11) -(-6/12)+x = 9/48
x= 9/48 - 6/12
x = -5/16
12) x - 4/6 = 5/25 + -7/15
x -4/6 = -4/15
x = -4/15 + 4/6
x = 2/5
Tìm x biết:
a) 6* 8^x-1 + 8^x+1 = 6* 8^19 + 8^21
b) 4* 3^x-1 + 2* 3^x+2 = 4* 3^6 +2* 3^9
a) \(6.8^{x-1}+8^{x+1}=6.8^{19}+8^{21}\)
\(\Rightarrow x-1+x+1=19+21\)
\(=2x=40\)
\(\Rightarrow x=20\)
b) \(4.3^{x-1}+2.3^{x+2}=4.3^6+2.3^9\)
\(\Rightarrow x-1+x+2=6+9\)
\(\Rightarrow2x+1=15\)
\(\Rightarrow2x=14\)
\(\Rightarrow x=7\)
Tìm x biết
x÷(2×2)+x÷(4×3)+x÷(6×4)+x÷(8×5)+x÷(10×6)
tìm số tn x biết
(x-2)^6=(x-2)6^8
Sửa đề
\(\left(x-2\right)^6=\left(x-2\right)^8\)
\(\Rightarrow\left(x-2\right)^6-\left(x-2\right)^8=0\)
\(\Rightarrow\left(x-2\right)^6\left[1-\left(x-2\right)^2\right]=0\)
\(\Leftrightarrow\orbr{\begin{cases}\left(x-2\right)^6=0\\1-\left(x-2\right)^2=0\end{cases}}\)
\(\Leftrightarrow\orbr{\begin{cases}x-2=0\\\left(x-2\right)^2=1\end{cases}}\)
\(\Leftrightarrow\orbr{\begin{cases}x=0+2\\\left(x-2\right)^2=\left(\pm1\right)^2\end{cases}}\)
\(\Leftrightarrow\hept{\begin{cases}x=2\\x-2=1\\x-2=-1\end{cases}}\)
\(\Leftrightarrow\hept{\begin{cases}x=2\\x=3\\x=1\end{cases}}\)
P/s : 2 dòng cuối bn chuyển \(\hept{\begin{cases}\\\\\end{cases}}\)thành \(\orbr{\begin{cases}\\\end{cases}}\)
Tìm số nguyên x , biết: a) x+21=6 B) x-10=-8 c) (-8)x=(-7).(-6)-2. d) 20+8.(x+3)=5².4
\(a,x+21=6\\ \Rightarrow x=-15\\ b,x-10=-8\\ \Rightarrow x=2\\ c,\left(-8\right)x=\left(-7\right)\left(-6\right)\\ \Rightarrow\left(-8\right)x=42\\ \Rightarrow x=-4\\ d,20+8\left(x+3\right)=5^2.4\\ \Rightarrow20+8\left(x+3\right)=25.4\\ \Rightarrow20+8\left(x+3\right)=100\\ \Rightarrow8\left(x+3\right)=80\\ \Rightarrow x+3=10\\ \Rightarrow x=7\)
\(a.x+21=6\\ x=6-21\\ x=-15\\ b.x-10=-8\\ x=-8+10\\ x=2\\ c.-8x=-7.\left(-6\right)-2\\ -8x=42-2\\ -8x=40\\ x=40:\left(-8\right)\\ x=-5\)
\(d.20+8\left(x+3\right)=5^2.4\\ 20+8x+24=25.4\\ 44+8x=100\\ 8x=100-44\\ 8x=56\\ x=56:8\\ x=7\)
a)x+21=6 b)x-10=-8
X=6-21 x=-8+10
X=-15 x=2
C)(-8).x=-7×(-6)-2 d)20+8.(x+3)=5^2.4
(-8).x=40 20+8.(x+3)=100
X=40÷8 8.(x+3)=100-20
X=5 8.(x+3)=80
X+3=80÷8
X+3=10
X=10-3=7
Tìm x biết (x-2)^8=(x-2)^6
\(\left(x-2\right)^8=\left(x-2\right)^6\)
\(\Leftrightarrow\left(x-2\right)^8-\left(x-2\right)^6=0\)
\(\Leftrightarrow\left(x-2\right)^6.\left[\left(x-2\right)^2-1\right]=0\)
Trường hợp 1: \(\left(x-2\right)^6=0\)
\(\Leftrightarrow\left(x-2\right)^6=0^6\)
\(\Leftrightarrow x-2=0\)
\(\Leftrightarrow x=2\)
Trường hợp 2: \(\left(x-2\right)^2-1=0\)
\(\Leftrightarrow\left(x-2\right)^2=1^2\)
\(\Leftrightarrow x-2=1\)
\(\Leftrightarrow x=3\)