tìm x
460 + 85 x 4 = ( x + 200) x 4
(x-7)(2x-8)=0
x -280 : 35=5x54
324 + 16x(2x+3)=404
Tìm số nguyên x
a) 0100 - (31 - x) = 40
b) 280 - (x - 140) : 35 = 270
c) ( 1900 - 2x) : 35 - 32 = 16
d) 2^2x-1 : 4 = 8^3
e) (x + 2)^5 = 2^10
f) (3x - 4) . (x - 1)^3 = 0
g) (-2x + 1)^2 = 49
h) 1+2+3+...+x = 78
a: =>31-x=60
=>x=-29
b: =>(x-140):35=280-270=10
=>x-140=350
=>x=490
c: =>(1900-2x):35=48
=>1900-2x=1680
=>2x=220
=>x=110
d: =>\(2^{2x-1}=2^9\cdot2=2^{11}\)
=>2x-1=11
=>x=6
e: =>(x+2)^5=4^5
=>x+2=4
=>x=2
f: =>3x-4=0 hoặc x-1=0
=>x=4/3 hoặc x=1
g: =>(2x-1)^2=49
=>2x-1=7 hoặc 2x-1=-7
=>x=-3 hoặc x=4
h: =>x(x+1)/2=78
=>x(x+1)=156
=>x=12
( x - 280 ) : 35 = 56 . 5
( x - 128 + 20 ) : 192 = 0
460 + 85 . 4 = ( x + 200 ) . 4
x + 5 . 2 - ( 32 + 16 . 3 : 16 - 15 ) = 0
1)\(\left(x-280\right):35=56.5\)
\(\left(x-280\right):35=280\)
\(x-280=280.35\)
\(x-280=9800\)
\(x=9800+280\)
\(x=10080\)
2) \(\left(x-128+20\right):192=0\)
\(\Rightarrow\left(x-148\right):192=0\)
\(\Rightarrow x-148=0\)
\(\Rightarrow x=0+148\)
\(\Rightarrow x=148\)
3) \(460+85.4=\left(x+200\right).4\)
\(\Rightarrow\left(x+200\right).4=460+340\)
\(\Rightarrow\left(x+200\right).4=800\)
\(\Rightarrow x+200=800:4=200\)
\(\Rightarrow x+200=200\)
\(\Rightarrow x=200-200=0\)
4) \(x+5.2-\left(32+16.3:16-15\right)=0\)
\(\Rightarrow x+10-\left(32+3-15\right)=0\)
\(\Rightarrow x+10-20=0\)
\(\Rightarrow x+10=20\)
\(\Rightarrow x=20-10=10\)
nha m.n
bài 1: tìm x thuộc Z
i) |x| - 3 =0
j) (-12).x = (-15).(-4) - 12
k) (7- |x| ). (2x - 4) = 0
L) 280 - (x-140) : 35 =270
i) |x| - 3 = 0
|x| = 0 + 3
|x| = 3
a)5. ( x + 35 ) = 515
b) (x+7):3=14c) 72:(x–15)=8
d) 19+(x+23)=50
e) (18–x) + 23 =29
f) 56–(x+14)=22g) (2x +1)–7=14
h) 3. (x+1)–32=67i) 70–5. (x–3)=45
j) 200–8. (2x+7)=112
k) 123–(x+4). 5 =38
\(a,\Rightarrow x+35=103\\ \Rightarrow x=68\\ b,\Rightarrow x+7=42\\ \Rightarrow x=35\\ c,\Rightarrow x-15=9\\ \Rightarrow x=24\\ d,\Rightarrow x+23=31\\ \Rightarrow x=8\\ e,\Rightarrow18-x=6\\ \Rightarrow x=12\\ f,\Rightarrow x+14=34\\ \Rightarrow x=20\\ g,\Rightarrow2x+1=21\\ \Rightarrow x=11\\ h,\Rightarrow3\left(x+1\right)=99\\ \Rightarrow x+1=33\Rightarrow x=32\\ i,5\left(x-3\right)=25\\ \Rightarrow x-3=5\\ \Rightarrow x=8\\ j,\Rightarrow8\left(2x+7\right)=88\\ \Rightarrow2x+7=11\Rightarrow x=2\\ k,\Rightarrow5\left(x+4\right)=85\\ \Rightarrow x+4=17\\ \Rightarrow x=13\)
Tìm x ϵ N biết :
a) 280 – ( x – 140 ) : 35 = 270 ;
b)( 190 – 2x ) : 35 – 32 = 16;
c) 720 : [ 41 – ( 2x – 5 ) ] = 23 .5
d) ( x : 23 + 45 ) . 37 – 22 = 24 . 105 ;
e) ( 3x – 4 ) . ( x – 1 ) 3 = 0 ;
f) 22x-1 : 4 = 83
g) x17 = x ;
h) ( x – 5 ) 4 = ( x – 5 ) 6 ;
i) ( x + 2 ) 5 = 210 ;
k ) 1 + 2 + 3 + … + x = 78
l) ( 3 .x – 24) . 73 = 2 .74 ;
n) 5x : 52 = 125 ;
m) ( x + 1) 2 = ( x + 1) 0 ;
o) ( 2 + x ) + ( 4 + x ) + ( 6 + x ) + ……+ ( 52 + x ) = 780 ;
p) 70⋮ x , 80 ⋮ x và x > 8
q) x ⋮ 12 , x ⋮ 25 , x ⋮ 30 và 0 < x < 500
Tìm điều kiện có nghĩa:
1) \(\sqrt{2x^2}\)
2) \(\sqrt{-x}\)
3) \(\sqrt{-x^2-3}\)
4) \(\sqrt{x^2+2x+3}\)
5) \(\sqrt{-a^2+8a-16}\)
6) \(\sqrt[]{16x^2-25}\)
7) \(\sqrt{4x^2-49}\)
8) \(\sqrt{8-x^2}\)
9) \(\sqrt{x^2-12}\)
10) \(\sqrt{x^2+2x-3}\)
11) \(\sqrt{2x^2+5x+3}\)
12) \(\sqrt{\dfrac{4}{x-1}}\)
13) \(\sqrt{\dfrac{-1}{x-3}}\)
14) \(\sqrt{\dfrac{-3}{x+2}}\)
15) \(\sqrt{\dfrac{1}{2a-1}}\)
16) \(\sqrt{\dfrac{2}{3-2a}}\)
17) \(\sqrt{\dfrac{-1}{2a-5}}\)
18) \(\sqrt{\dfrac{-2}{3-5a}}\)
19) \(\sqrt{\dfrac{-a}{5}}\)
20) \(\dfrac{1}{\sqrt{-3a}}\)
1) \(ĐK:x\in R\)
2) \(ĐK:x< 0\)
3) \(ĐK:x\in\varnothing\)
4) \(=\sqrt{\left(x+1\right)^2+2}\)
\(ĐK:x\in R\)
5) \(=\sqrt{-\left(a-4\right)^2}\)
\(ĐK:x\in\varnothing\)
Tìm x:
a, -1/3. (15x-9)+ 2/7. (-x-34)= 1- 3/4. (-16x+4)
b, -1/3. (x-5)+ 1/2. (2x-1/3) = -4.(x+1/2) -7
c, 3.(-2x+7) -6. (1/2x) =1.(x-3)
a; - \(\dfrac{1}{3}\).(15\(x-9\)) + \(\dfrac{2}{7}\).(- \(x-34\)) = 1 - \(\dfrac{3}{4}\).(-16\(x+4\))
- 5\(x\) + 3 - \(\dfrac{2}{7}\)\(x\) - \(\dfrac{68}{7}\) = 1 + 12\(x\) - 3
12\(x\) + 5\(x\) + \(\dfrac{2}{7}x\) = 3 - \(\dfrac{68}{7}\) - 1 + 3
17\(x\) + \(\dfrac{2}{7}x\) = (3 - 1 + 3) - \(\dfrac{68}{7}\)
\(\dfrac{121}{7}\)\(x\) = 5 - \(\dfrac{68}{7}\)
\(\dfrac{121}{7}\) \(x\) = - \(\dfrac{33}{7}\)
\(x\) = - \(\dfrac{33}{7}\): \(\dfrac{121}{7}\)
\(x\) = - \(\dfrac{3}{11}\)
Vậy \(x\) = - \(\dfrac{3}{11}\)
tìm x:
a.(x-3)^4-(x+3)^4+24x^3=216
b.(2x+1)(16x^4-8x^3+4x^2-2x+1)-(2x-1)(16x^4+8x^3+4x^2+2x+1)=2
tìm GTNN của bt:
x^2+2x+4
x^2-x-5/3/4
4x^2-x-3/16
tìm x biết :
a,(2x+ 4/5) (3x-1/2)= 0
b,(x-2/5) (x+4/7)= 0
c,-1 =|x- 5/6|= 1/2
d,x+ 5/8 x- 12/16x= 1
a. 2x+\(\dfrac{4}{5}\)=0 hoặc 3x-\(\dfrac{1}{2}\)=0
2x=- 4/5 hoặc 3x=1/2
x=-2/5 hoặc x=\(\dfrac{1}{6}\)
b. x-\(\dfrac{2}{5}\)=0 hoặc x+\(\dfrac{4}{7}\)=0
x=2/5 hoặc x=-\(\dfrac{4}{7}\)
d. x(1+5/8-12/16)=1
\(\dfrac{7}{8}\)x=1=> x=8/7