x+10/27=x/9 tìm x e Z
tìm số nguyên x,y,z ;
a) 6/5 = 18/x
b) 3/4 = -21/x
c) x/4 = 21/28
d) -8/2x = 3/-9
e) -4/11 = x/22 = 40/z
f) - 3/4 = x/20 = 21 / y
g) -4/8 = x/-10 = -7/y = z/-24
h) x/4 = 9/x
\(a.\dfrac{6}{5}=\dfrac{18}{x}\Rightarrow x=\dfrac{18\cdot5}{6}=15\\ \text{Vậy}\text{ }x=15.\)
\(b.\dfrac{3}{4}=\dfrac{-21}{x}\Rightarrow x=\dfrac{-21\cdot4}{3}=28\\ \text{ }\text{ }\text{ }\text{ }\text{Vậy }x=28.\)
\(c.\dfrac{x}{4}=\dfrac{21}{28}\Rightarrow x=\dfrac{21\cdot4}{28}=3\\ \text{Vậy }x=3.\)
\(d.\dfrac{-8}{2x}=\dfrac{3}{-9}\Rightarrow x=\dfrac{-8\cdot\left(-9\right)}{3}:2=12\\ \text{Vậy }x=12.\)
\(e.\dfrac{-4}{11}=\dfrac{x}{22}=\dfrac{40}{z}\\ \Rightarrow x=\dfrac{-4\cdot22}{11}=-8\\ \Rightarrow z=\dfrac{22\cdot40}{-8}=-110\\ \text{Vậy }x=-8;z=-110.\)
\(f.\dfrac{-3}{4}=\dfrac{x}{20}=\dfrac{21}{y}\\ \Rightarrow x=\dfrac{-3\cdot20}{4}=-15\\ \Rightarrow y=\dfrac{21\cdot20}{-15}=-28\\ \text{Vậy }x=-15;y=-28.\)
\(g.\dfrac{-4}{8}=\dfrac{x}{-10}=\dfrac{-7}{y}=\dfrac{z}{-24}\\ \Rightarrow x=\dfrac{-4\cdot\left(-10\right)}{8}=5\\ \Rightarrow y=\dfrac{-7\cdot\left(-10\right)}{5}=14\\ \Rightarrow z=\dfrac{-7\cdot\left(-24\right)}{14}=12\\ \text{Vậy }x=5;y=14;z=12.\)
\(h.\dfrac{x}{4}=\dfrac{9}{x}\\ \Rightarrow x\cdot x=9\cdot4\\ \Rightarrow x\cdot x=36\\ \Rightarrow x\cdot x=6\cdot6\\ \text{Vậy }\text{cả hai }x=6.\)
Tìm x thuộc Z, biết:
a)27<20+|x|<32
b)-12+[|x|+(-9)] = (-5)2 -21
c) x-{x- [x-(-x+1)]}=1
d) (x+3).(2x+10).(x4+5) =0
Tìm \(x\in Z\)
( 10 - x ) . ( x - 10 ) + 9 = 5
( 10 - x ) . ( x - 10 ) + 9 = 5
1 . ( 10 - x ) . ( x - 10 ) = 5 - 9
( - 1 ) [ - ( 10 - x ) ] . ( x - 10 ) = - 4
( - 1 ) . ( - 10 + x ) . ( x - 10 ) = - 4
( - 1 ) . ( x - 10 ) . ( x - 10 ) = - 4
( x - 10 ) . ( x - 10 ) = ( - 4 ) : ( - 1 )
( x - 10 )2 = 4
( x - 10 ) 2 = 22 hoặc ( x - 10 )2 = ( - 2 )2
=> x - 10 = 2 hoặc x - 10 = - 2
x = 2 + 10 hoặc x = - 2 + 10
x = 12 hoặc x = 8
Vậy x \(\in\){ 12 ; 8 }
\(\left(10-x\right)\left(x-10\right)+9=5\)
\(10x-100-x^2+10x=-4\)
\(-x^2+20x=96\)
\(-x^2+20x-96=0\)
\(x^2-20x+96=0\)
đến đây tách rồi phân tích tiếp
Tìm x biết: \(\frac{x+10}{27}=\frac{x}{9}\)
\(\frac{x+10}{27}=\frac{x}{9}\)
\(\frac{x+10}{27}=\frac{3x}{27}\)
=>x+10=3x
10=3x-x
10=2x
x=10:2
x=5
\(\frac{x+10}{27}=\frac{x}{9}\)
=> \(\frac{x+10}{27}=\frac{x\cdot3}{27}\)
=> \(x+10=x\cdot3\)
Rồi bạn tự làm nhé ?
Tìm x thuộc Z biết:
a) (x+1)+(x+2)+(x+3)+...+(x+99)=0
b)(x-3)+(x-2)+(x-1)+...+9+10+11=11
Tìm x,y,z
3x=2y
2x=z
và x+y+z=27
1. Tìm x thuộc Z
a) /15-x/=/-2/+/-3/
b)//x-1/+5/=4
c)/x : (x;10)/=0
d)/(x^2-4).(x^2-16)/=0
e)/10-x^2/+15=14
g)/x+3/-4<5
k)/15-x/+4>9
m)/x(x+3)/+/x(x-5)/=6
n)/x-3/=/2x-3/
a, => |15-x| = 2+3
=> |15-x| = 5
=> 15-x = -5 hoặc 15-x = 5
=> x = 10 hoặc x = 10
Vậy ......
Tk mk nha
a/|15-x|=|-2|+|-3|
=>|15-x|=2+3=5
=>\(15-x=\hept{\begin{cases}5\\-5\end{cases}}\)
=>\(x=\hept{\begin{cases}10\\15\end{cases}}\)
.........
k nha , thanks
Tính:
a) 2^5 x 13^12 x 7^8 : 27 x 13^10 x 7^9
b) 2^n x 11 x 3 : 6^n x 3
c) 5^5 x 7 x 9^5 : 15^10
d) 7 x 8^10 x 27^9 - 8 x 9^13 x 2^27 : 7 x 6^26 x 2^2 - 2^4 x 8^3 x 27^9
e) 2^2^1^2015
f) 2015^0^2015^0^2015
Tìm x,y,z
3x=2y
2x=z
và x+y+z=27
x/2=y/3
x/1=z/2
=>x/2=y/3=z/4=x+y+z=2+3+4=27/9=3
Vậy x=6
y=9
z=12