1) x^2 + x - 6
2) x^2 - x - 6
3) x^2 + 2x - 48
4) x^2 - 2x -48
5) x^2 + x- 42
6) x^2 - x-42
38 x 2 = ? | 77 x 3 = ? |
26 x 4 = ? | 54 x 6 = ? |
42 x 5 = ? | 48 x 3 = ? |
38x2=76
26x4=104
42x5=210
77x3=231
54x6=324
48x3=144
38x2=76 ;77x3=231 ;26x4=104 ;54x6=324 ;42x5=210 ;48x3=144
38 x 2 = 76
26 x 4 = 104
42 x 5=210
77 x 3 = 231
54 x 6 = 324
48 x 3 =144
HOK TỐT -_-
a) x+2/x-2-1/x=2/x*(x-2)
b)2/2x-6+2/2x+2+2x/(x+1)*(3-x)=0
c) x+1/2017+x+2/2016=x+3/2015+x+4/2014
d) x-45/5+x-44/6+x-43/7+x-42/8=4
e) x-3/2011+x+2/2012=x-2012/2+x-2011/3
a) ĐKXĐ: \(x\notin\left\{0;2\right\}\)
Ta có: \(\dfrac{x+2}{x-2}-\dfrac{1}{x}=\dfrac{2}{x\left(x-2\right)}\)
\(\Leftrightarrow\dfrac{x\left(x+2\right)}{x\left(x-2\right)}-\dfrac{x-2}{x\left(x-2\right)}=\dfrac{2}{x\left(x-2\right)}\)
Suy ra: \(x^2+2x-x+2-2=0\)
\(\Leftrightarrow x^2+x=0\)
\(\Leftrightarrow x\left(x+1\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}x=0\\x+1=0\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=0\left(loại\right)\\x=-1\left(nhận\right)\end{matrix}\right.\)
Vậy: S={-1}
tm x
a,(3x-17).4^5=4^6
b,3 |x-5|-23=(-2)^3
c,96-3 (x+1)=42
d,48:(2x+1)-7=5
e,4.(x+1)^3-5=3^3
a) ( 3x-17) . 45= 46
( 3x -17) = 46: 45
( 3x-17) = 4
3x = 4+17
3x= 21
x= 21:3
x=7
Vậy....
b) 3 |x-5|-23=(-2)3
3 |x-5| -23 = -8
3 |x-5| = -8+23
3 |x-5| = 15
| x -5| = 15:3
|x-5| = 5
TH1: x- 5= 5
x= 5+5
x= 10
TH2: x -5 = -5
x= -5+5
x= 0
Vậy...
c) 96-3 (x+1)=42
3 ( x+1) = 96-42
3(x+1) = 54
x+1 = 54:3
x+1 = 18
x= 18-1
x= 17
Vậy...
1) (3x-2)/3-2=(4x+1)/42) (x-3)/4+(2x-1)/3=(2-x)/63) 1/2 (x+1)+1/4 (x+3)=3-1/3 (x+2)4) (x+4)/5-x+4=x/3-(x-2)/25) (4-5x)/6=2(-x+1)/2 6) (-(x-3))/2-2=5(x+2)/4 7)2(2x+1)/5-(6+x)/3=(5-4x)/158) (7-3x)/2-(5+x)/5=1 9)(x-1)/2+3(x+1)/8=(11-5x)/310)(3+5x)/5-3=(9x-3)/4
Bài 1 : tì x thuộc z
a) -12(x-5)+7(3-x)=5
b) 30(x+2)-6(x-5)-24x=100
c) (x-23):14+25=42-1^2002
d) (x-5^6)= (x-5^4)
e) 2^3.x+2002^0.x=995-15:3
g) x+2x+3x+....+9x=459-3^2
h) 13x+(-3^2x) = 2003^1+1^2003
k) 2^5x+3^3x= 6.100-10.205^0
l) x-6:2-(48-24):2:6-3=0
bài 2 tìm x thuộc z
a) /x/=/x+8/
b)/x/=/x/
c)/x/+/x/=0
các bạn giúp mình nhé
\(a,-12\left(x-5\right)+7\left(3-x\right)=5\)
\(-12x+60+21-7x=5\)
\(-12x-7x=5-60-21\)
\(-19x=-76\Leftrightarrow x=4\)
\(b,30\left(x+2\right)-6\left(x-5\right)-24x=100\)
\(30x+60-6x+30-24x=100\)
\(30x-6x-24x=100-60-30\)
\(0x=10\left(vl\right)\)
Vậy pt vô nghiệm
\(c,\left(x-23\right):14+25=42-1^{2002}\)
\(\left(x-23\right).\frac{1}{14}+25=42-1\)
\(\frac{x}{14}-\frac{23}{14}+25=41\)
\(\frac{x}{14}-\frac{23}{14}=16\)
\(\frac{x}{14}=\frac{247}{14}\)
\(x=247\)
Tìm x
a , x - 6 : 2 - ( 48 - 24 ) : 2 : 6 - 3 = 0
c , 42 - 2 * ( x + 16 ) + 12 : 2 = 6
d , ( 697 : 17 ) * x = 672 - 15 * x
e , 8 * x = 75 : 3 + 35 - 2 : x
g , 3 * x - 15 * 4 = 6 * ( 2 - x )
h , 129 - 5 * ( x + 1 ) = 98 + ( 136 : 17 ) * x
Tính nhanh
G= 2 x 31 x 12 + 4 x 6 x 42 + 8 x 27 x 3
C = 46 - 45 + 44 -43 + 42 - 41 + .... + 2 -1
I = 7 x 48 x 6 + 21 x 12 x 2 +14 x 40 x 3
( Giải ra )
Dãy số có 2 chữ số chia hết cho 3 là:[12,15,....,99]
Khoảng cách của từng số hạng là 3
Số số hạng là: (99-12):3+1=30(số)
Vậy có 30 số có 2 chữ số chia hết cho 3
A, (x-4)(x-5)=12
B,(2x-2)(2x-4)=3
C,(x-5)(x+6)=42
D, (2x-1)(x+3)=-6
a) \(⇔x^2-9x+20=12 \)
\(⇔x^2-9x+8=0\)
\(⇔x^2-x-8x+8=0\)
\(⇔(x-1)(x-8)=0\)
\(⇔\left[\begin{array}{} x-1=0\\ x-8=0 \end{array}\right.⇔\left[\begin{array}{} x=1\\ x=8 \end{array}\right.\)
b) \(⇔4x^2-12x+8=3\)
\(⇔4x^2-12x+5=0\)
\(⇔(2x-1)(2x-5)=0\)
\(⇔\left[\begin{array}{} 2x-1=0\\ 2x-5=0 \end{array}\right.⇔\left[\begin{array}{} x=\frac{1}{2}\\ x=\frac{5}{2} \end{array}\right.\)
c) \(⇔x^2+x-30=42\)
\(⇔x^2+x-72=0\)
\(⇔(x-9)(x+8)=0\)
\(⇔\left[\begin{array}{} x-9=0\\ x+8=0 \end{array}\right.⇔\left[\begin{array}{} x=9\\ x=-8 \end{array}\right.\)
d) \(⇔2x^2+5x-3=-6\)
\(⇔2x^2+5x+3=0\)
\(⇔(x+1)(2x+3)=0\)
\(⇔\left[\begin{array}{} x+1=0\\ 2x+3=0 \end{array}\right.⇔\left[\begin{array}{} x=-1\\ x=-\frac{3}{2} \end{array}\right.\)
A, (x-4)(x-5)=12
B,(2x-2)(2x-4)=3
C,(x-5)(x+6)=42
D, (2x-1)(x+3)=-6
Đề bài là j vậy bạn?