Tìm x :
a) X : 5 + 24 = 33
b) 5 + X x 2 = 25
Tìm x biết :
a) 12 - 3x = 33
b) ( x + 1)(2 - x) - (3x + 5)(x + 2) = -4x2 + 2
a: \(\Leftrightarrow3x=-21\)
hay x=-7
Tìm x :
a) 2x - 52 = 33
b) 5. ( x + 35 ) = 515
c) 4x+1 = 64
d) 3 222 - ( x -235 ) = 2357
\(a,\Rightarrow2x-25=33\\ \Rightarrow2x=58\\ \Rightarrow x=29\\ b,\Rightarrow x+35=103\\ \Rightarrow x=68\\ c,\Rightarrow4^{x+1}=4^3\\ \Rightarrow x+1=3\\ \Rightarrow x=2\\ d,\Rightarrow x-235=865\\ \Rightarrow x=1100\)
tìm x,y
A) \(\dfrac{x}{y}=\dfrac{7}{4}\) và x+y=33
b) 3.(x-1)+5=-19
a,Ta có:
\(\dfrac{x}{y}=\dfrac{7}{4}=\dfrac{x}{7}=\dfrac{y}{4}\)
ÁP dụng tcdtsbn , ta có:
\(\dfrac{x}{7}=\dfrac{y}{4}=\dfrac{x+y}{7+4}=\dfrac{33}{11}=3\)
\(\Rightarrow\left\{{}\begin{matrix}x=21\\y=12\end{matrix}\right.\)
b,
\(\Rightarrow3.\left(x-1\right)=-24\)
\(\Rightarrow x-1=-8\)
\(\Rightarrow x=-7\)
A)\(\dfrac{x}{y}=\dfrac{7}{4}\Rightarrow\dfrac{x}{7}=\dfrac{y}{4}\)
Áp dụng t/c dtsbn ta có:
\(\dfrac{x}{7}=\dfrac{y}{4}=\dfrac{x+y}{7+4}=\dfrac{33}{11}=3\)
\(\dfrac{x}{7}=3\Rightarrow x=21\\ \dfrac{y}{4}=3\Rightarrow y=12\)
B) \(3\left(x-1\right)+5=-19\\ \Rightarrow3\left(x-1\right)=-24\\ \Rightarrow x-1=-8\\ \Rightarrow x=-7\)
bài 1: tìm x thuộc Z
a) 10-x-5=(-5)-7-11
b) (x-3)-(x+17-24)-(25-x)=24-(-30)
c) (7-9x)-(2x-4)=-(5.x+35)-(-27)-(+25)
a: =>5-x=-23
=>x=5+23=28
b: =>x-3-x+7-25+x=54
=>x-21=54
=>x=75
c: =>7-9x-2x+4=-5x-35+27-25=-5x-37
=>-11x+3=-5x-37
=>-6x=-40
=>x=20/3
a) \(10-x-5=\left(-5\right)-7-11\)
\(\Rightarrow5-x=-23\)
\(\Rightarrow x=5+23\)
\(\Rightarrow x=28\)
b) \(\left(x-3\right)-\left(x+17-24\right)-\left(25-x\right)=24-\left(-30\right)\)
\(\Rightarrow x-3-x-17+24-25+x=54\)
\(\Rightarrow x-21=54\)
\(\Rightarrow x=54+21\)
\(\Rightarrow x=75\)
c) \(\left(7-9x\right)-\left(2x-4\right)=-\left(5x+35\right)-\left(-27\right)-25\)
\(\Rightarrow7-9x-2x+4=-5x-35+27-25\)
\(\Rightarrow11-11x=-5x-33\)
\(\Rightarrow-11x+5x=-33-11\)
\(\Rightarrow-6x=-22\)
\(\Rightarrow x=\dfrac{22}{6}=\dfrac{11}{3}\)
a.
10-x-5 = (-5) - 7 -11
=>5-x = 0
=>x=5
b
(x-3) - (x+17-24) - (25-x) = 24 - (-30)
=>x - 3 - x - 17 + 24 - 25 - x = 24 + 30
=>-x - 21 = 54
=>-x = 75
=>x = -75
c
(7 - 9x) - (2x - 4) = - (5x + 35) - (-27) - 25
=>7-9x - 2x + 4 = -5x - 35 + 27 - 35
=>11 - 11x + 5x = -43
=>16x = 11 + 43
=>16x = 54
=>x=4
Tìm các số x, y, z biết:
a) \(\dfrac{x}{2}=\dfrac{y}{3}=\dfrac{z}{5}\) và x - 2y + 3z = 33
b) x : y : z = 10 : 6 : 21 và y + 5x - 2z = -42
a: Áp dụng tính chất của dãy tỉ số bằng nhau, ta được:
\(\dfrac{x}{2}=\dfrac{y}{3}=\dfrac{z}{5}=\dfrac{x-2y+3z}{2-2\cdot3+3\cdot5}=\dfrac{33}{11}=3\)
Do đó: x=6; y=9; z=15
tìm x thuộc số hữu tỉ
a, x-1/x+5 = 6/7 (x#5)
b,x^2/6 = 24/25
c,(x-2)/x-1 = x+4/(x+7) (x#19,x#-7)
Tìm x, biết:
a) (x - 3.5).12 = 0;
b) 35. (x - 10) = 35;
c) ( x - 5): 3 + 3 = 24
d) ( x - 4) : 3 - 2 = 100
c) 25.(2.x - 4).12 = 0
d) (x - 4) : 6 - 5 = 10
Tìm x, biết:
a) (x - 3.5).12 = 0; b) 35. (x-10) = 35;
c) ( x -5): 3 + 3 = 24 d) ( x- 4) : 3 - 2 = 100
c) 25.(2.x - 4).12 = 0 d) (x- 4) : 6 - 5 = 10
a) x = 15. b) x = 11. c) x = 68. d) x = 310
Tìm xx biết: \left(x^{4}\right)^{3}=\dfrac{x^{19}}{x^{6}}(x4)3=x6x19
Trả lời: x=x=
bài 19: tìm x
a) 5 . ( x - 7 ) = 0
b) 25 ( x - 4 ) = 0
c) ( 34 - 2x ) . ( 2x - 6 ) = 0
d) ( 2019 - x ) . ( 3x - 12 ) 0
e) 57 . ( 9x - 27 ) = 0
f) 25 + ( 15 - x ) = 30
g) 43 - ( 24 - x ) = 20
h) 2 . ( x - 5 ) - 17 = 25
i) 3 . ( x + 7 ) - 15 = 27
j) 15 + 4 . ( x - 2 ) = 95
k) 20 - ( x + 14 ) = 5
l) 14 + 3 . ( 5 - x ) = 27
a) \(5\left(x-7\right)=0\)
\(\Rightarrow x-7=0\)
\(\Rightarrow x=7\)
b) \(25\left(x-4\right)=0\)
\(\Rightarrow x-4=0\)
\(\Rightarrow x=4\)
c) \(\left(34-2x\right)\left(2x-6\right)=0\)
\(\Rightarrow\left[{}\begin{matrix}34-2x=0\\2x-6=0\end{matrix}\right.\)
\(\Rightarrow\left[{}\begin{matrix}2x=34\\2x=6\end{matrix}\right.\)
\(\Rightarrow\left[{}\begin{matrix}x=17\\x=3\end{matrix}\right.\)
d) \(\left(2019-x\right)\left(3x-12\right)=0\)
\(\Rightarrow\left[{}\begin{matrix}2019-x=0\\3x-12=0\end{matrix}\right.\)
\(\Rightarrow\left[{}\begin{matrix}x=2019\\3x=12\end{matrix}\right.\)
\(\Rightarrow\left[{}\begin{matrix}x=2019\\x=\dfrac{12}{3}=4\end{matrix}\right.\)
e) \(57\left(9x-27\right)=0\)
\(\Rightarrow9x-27=0\)
\(\Rightarrow9\left(x-3\right)=0\)
\(\Rightarrow x-3=0\)
\(\Rightarrow x=3\)
a) 5.(x-7)=0⇔x-7=0⇔x=7
b) 25(x-4)=0⇔x-4=0⇔x=4
c) (34-2x).(2x-6)=0
⇔ 34-2x=0 hoặc 2x-6=0
⇔2x=34 hoặc 2x=6
⇔ x=17 hoặc x=3
d) (2019-x).(3x-12)=0
⇔ 2019-x=0 hoặc 3x-12=0
⇔ x=2019 hoặc x=4
e) 57.(9x-27)=0
⇔ 9x-27=0
⇔ x=3
f) 25+(15-x)=30
⇔ 15-x=5
⇔ x=10
g) 43-(24-x)=20
⇔ 24-x=23
⇔ x=1
h) 2.(x-5)-17=25
⇔ 2(x-5)=42
⇔x-5=21
⇔ x=26
i) 3(x+7)-15=27
⇔ 3(x+7)=42
⇔ x+7=14
⇔ x=7
j) 15+4(x-2)=95
⇔ 4(x-2)=80
⇔ x-2=20
⇔ x=22
k) 20-(x+14)=5
⇔ x+14=15
⇔ x=1
l) 14+3(5-x)=27
⇔ 3(5-x)=13
⇔ 5-x=13/3
⇔ x=5-13/3
⇔ x=2/3