Tìm x biết
d)12.x - 33= 3 2 . 3 3
tìm x biết
d) 9x^ 2 + 6x - 8 = 0.
e) x(x - 2) + x - 2 = 0;
f) 5x(x - 3) - x + 3 = 0
Mình trình bày trong hình ^^ Bn tham khảo nhé
d: Ta có: \(9x^2+6x-8=0\)
\(\Leftrightarrow9x^2+12x-6x-8=0\)
\(\Leftrightarrow\left(3x+4\right)\left(3x-2\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}x=-\dfrac{4}{3}\\x=\dfrac{2}{3}\end{matrix}\right.\)
e: Ta có: \(x\left(x-2\right)+x-2=0\)
\(\Leftrightarrow\left(x-2\right)\left(x+1\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}x=2\\x=-1\end{matrix}\right.\)
f: Ta có: \(5x\left(x-3\right)-x+3=0\)
\(\Leftrightarrow\left(x-3\right)\left(5x-1\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}x=3\\x=\dfrac{1}{5}\end{matrix}\right.\)
Tìm x biết
d) 32%-0,25:x=-17/5
e)(x+1/5)^2+17/25=26/25
f)-32/27-(3x-7/9)^3=-24/27
g)60%x+0,4x+x:3=2
h)|20/9-x|=1/12+1/20+1/30+1/42+1/56+1/72
i)8/5+(2/7+2/17+2/37/5/7+5/17+5/37).x=16/5
Lưu ý: câu i 2/7+2/17+2/37 phần(vế trên) 5/7+5/17+5/37(vế dưới)
d) Ta có: \(32\%-0.25:x=-\dfrac{17}{5}\)
\(\Leftrightarrow0.25:x=\dfrac{8}{25}+\dfrac{17}{5}=\dfrac{93}{25}\)
hay \(x=\dfrac{25}{372}\)
Vậy: \(x=\dfrac{25}{372}\)
e) Ta có: \(\left(x+\dfrac{1}{5}\right)^2+\dfrac{17}{25}=\dfrac{26}{25}\)
\(\Leftrightarrow\left(x+\dfrac{1}{5}\right)^2=\dfrac{9}{25}\)
\(\Leftrightarrow\left[{}\begin{matrix}x+\dfrac{1}{5}=\dfrac{3}{5}\\x+\dfrac{1}{5}=-\dfrac{3}{5}\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=\dfrac{2}{5}\\x=-\dfrac{4}{5}\end{matrix}\right.\)
Vậy: \(x\in\left\{\dfrac{2}{5};-\dfrac{4}{5}\right\}\)
f) Ta có: \(-\dfrac{32}{27}-\left(3x-\dfrac{7}{9}\right)^3=-\dfrac{24}{27}\)
\(\Leftrightarrow\left(3x-\dfrac{7}{9}\right)^3=\dfrac{-8}{27}\)
\(\Leftrightarrow3x-\dfrac{7}{9}=-\dfrac{2}{3}\)
\(\Leftrightarrow3x=\dfrac{1}{9}\)
hay \(x=\dfrac{1}{27}\)
g) Ta có: \(60\%\cdot x+0.4x+x:3=2\)
\(\Leftrightarrow\dfrac{4}{3}x=2\)
hay \(x=\dfrac{3}{2}\)
Vậy: \(x=\dfrac{3}{2}\)
h) PT \(\Leftrightarrow\left|\dfrac{20}{9}-x\right|=\dfrac{2}{9}\) \(\Rightarrow\left[{}\begin{matrix}\dfrac{20}{9}-x=\dfrac{2}{9}\\x-\dfrac{20}{9}=\dfrac{2}{9}\end{matrix}\right.\) \(\Leftrightarrow\left[{}\begin{matrix}x=2\\x=\dfrac{22}{9}\end{matrix}\right.\)
Vậy ...
i) PT \(\Leftrightarrow\dfrac{8}{5}+\dfrac{2}{5}x=\dfrac{16}{5}\) \(\Leftrightarrow\dfrac{2}{5}x=\dfrac{8}{5}\) \(\Leftrightarrow x=4\)
Vậy ...
Tìm x
12 x -33=3^2 . 3^3
12x-33=9.27
12x-33=243
12x=243+33
12x=276
x=276:12
x=23
12 x- 33= 3^2 . 3^3
12 x- 33= 3^5
12 x- 33=243
12 x =243+ 33
12 x = 276
x =276:12
x = 23
Vậy x = 23
tìm x 14,73:x+21,27:x-12:x=33-3*3*3
14,73 : x + 21,27 : x - 12 : x = 33-3x3x3
<=> ( 14,73 + 21,27 - 12 ) : x = 33 - 27 = 6
<=> 24 : x = 6
=> x = 24 : 6 = 4
14,73 : x + 21,27 : x - 12 : x = 33 - 3 * 3 * 3
14,73 : x + 21,27 : x - 12 : x = 6
HAY: ( 14,73 + 21,27 - 12 ) : x = 6
24 : x = 6
x = 24 : 6
x = 4
chúc bạn học tốt nhé !!! ^_^
vì x xuất hiện nhiều lần nên chúng ta sẽ lấy x làm thừa số chung
[14,73+21,27-12]:x =33-27
24 : x =6
x =24: 6
x=4
nhớ nha
tìm x
5.(x+35)=515
12.x-33=32.33
12.(x-1):3=43-23
(2x-4)3=23.32+360
\(a,5.\left(x+35\right)=515\)
\(x+35=103\)
\(x=103-35\)
\(x=68\)
\(b,12.x-33=3^2.3^3\)
\(12x-33=243\)
\(12x=276\)
\(x=23\)
\(d,12.\left(x-1\right):3=4^3-2^3\)
\(12.\left(x-1\right):3=56\)
\(12.\left(x-1\right)=168\)
\(x-1=14\)
\(x=15\)
Tìm x
a) ( x - 35 ) - 120 = 0
b) 156 - ( x + 61 ) = 82
c) 12.x - 33 = 32.33
(x-35)-120=0
x-35=120
x=155
156-(x+61)=82
-(x+61)=-74
x+61=74
x=13
12x-33=3^2.3^3
12x-33=243
12x=276
x=23
Tìm số tự nhiên x,biết:
a)58 + 7x = 100
b) ( x –12):12=12
c) x -56 : 4= 16
d) 101 +(36 –4x) =105
e) 2(x-51) = 2.23+ 20
f) 10 -(x –3): 2 = 72–110
g) 2x –49 = 5.32h) [(8x -12) : 4].33= 36
i) 52x –3–2 . 52= 52. 3 k) (x3–7) : 4 = 5
a: 7x+58=100
nên 7x=42
hay x=6
c: x-56:x=16
nên x-14=16
hay x=30
c)x - 56 : 4 = 16
x - 56 = 16 : 4
x- 56 = 4
x =4 + 56
x = 60
d)101 + (36 - 4x) = 105
(36- 4x ) = 105 - 101
36 - 4x = 4
4x = 36 - 4
4x = 32
x = 32:4
x = 8
a) 58 + 7x = 100
7x = 100 - 58
7x = 42
x = 42 : 7
x = 6
b) (x - 12) : 12 = 12
x - 12 = 12 . 12
x - 12 = 144
x = 144 + 12
x = 156
Bài 13: Tìm x biết: a) (x-2)(x-3)-D0. b) (x-3)(x-4)-0. c) (x-7)(6-x)=0. d) (x-3)(x-13)=0. The Bài 14: Tìm x biết: a) (12-x)(2-x)=0. b) (x-33)(11-x)=0. c) (21-x)(12-x)=0. d) (50-x)(x-150) =0. Bài 15: Tìm x biết: a) 2x +x = 45. b) 2x +7x = 918. c) 2x+3x 60+5. d) 11x+22x 33.2.
Tìm X
e) – 40 – (– 3 – 33) + (40 – x) = – (– 47) f) x(3x – 9). (121 – x2) = 0
g) – 62 – (38 + x) + 2x = – 100 h) (x + 1)2.(x2 + 1) = 0
i) (x – 12) – (2x + 31) = 6 k) 17/ (x + 3)3 : 3 – 1 = – 10
e: =>-40+3+33+40-x=47
=>36-x=47
=>x=-11
f: =>x(x-3)(11-x)(11+x)=0
hay \(x\in\left\{0;3;11;-11\right\}\)
g: =>-62-38-x+2x=-100
=>x-100=-100
hay x=0
Tìm X
e) – 40 – (– 3 – 33) + (40 – x) = – (– 47) f) x(3x – 9). (121 – x2) = 0
g) – 62 – (38 + x) + 2x = – 100 h) (x + 1)2.(x2 + 1) = 0
i) (x – 12) – (2x + 31) = 6 k) 17/ (x + 3)3 : 3 – 1 = – 10