3/2x-(4/5-2x)=13/10. (Giúp mik với,27/6 thi rồi)
a)3/2x-4/5+2x=13/10
b) chứng tỏ 1/22+1/32+1/42+...+1/20182<1
Các bạn giúp mik với,sắp thi r,cảm ơn nhiều
\(A=\frac{1}{2^2}+\cdot\cdot\cdot+\frac{1}{2018^2}\)<\(\frac{1}{1\cdot2}+\cdot\cdot\cdot+\frac{1}{2017\cdot2018}\)
\(\Rightarrow A\)<\(1-\frac{1}{2}+\cdot\cdot\cdot+\frac{1}{2017}-\frac{1}{2018}\)
\(\Rightarrow A\)<\(1-\frac{1}{2018}\)<\(1\)
Tìm x:
2x-10 /6 = -27/5-x
(ý mik là 2x-10 phần 6 nha)
Giúp mik với, cám ơn các bạn nhìu
\(\frac{2x-10}{6}=\frac{-27}{5-x}\)
\(\frac{2\left(x-5\right)}{6}=\frac{27}{x-5}\)
\(2\left(x-5\right)^2=27\times6\)
\(2x^2-20x+50-162=0\)
\(2x^2-20x-112=0\)
\(x^2-10x-56=0\)
\(x^2-14x+4x-56=0\)
\(\left(x-14\right)\left(x+4\right)=0\)
\(\Leftrightarrow\orbr{\begin{cases}x-14=0\\x+4=0\end{cases}}\Leftrightarrow\orbr{\begin{cases}x=14\\x=-4\end{cases}}\)
KL .....
XIN TIICK
. Help Me ! Please :)) Mik đang gấp lắm nhé nên nếu các bạn biết thì giải giúp mik nhé :3 Cảm ơn nhiều nhiều lắm nek ~~~ Bạn nào làm đúng mik sẽ tik nhé =)) Phần nào các bạn làm đk thì giúp mik, bài dài nên mik ko mún làm mất quá nhìu thời gian các bạn đâu ^^
~ ĐỀ BÀI: Phân tích các đa thức sau thành nhân tử
1) 6x^2 - 11x + 3
2) 2x^2 + 3x - 27
3) 2x^2 - 5xy - 3y^2
4) x^3 + 2x - 3
5) x^3 - 7x + 6
6) x^3 - 9x^2 + 6x + 16
7) x^3 + x^2 - x + 2
8) x^3 - 6x^2 - x + 30
9) 4x^4 - 32x^2 + 1
10) x^6 + 27
11) 4x^4 + 1
12) (x^2-2x).(x^2 - 2x - 1) - 6
13) x^2 - 2xy + y^2 + 3x - 3y - 4
Ta có : 6x2 - 11x + 3
= 6x2 - 2x - 9x + 3
= (6x2 - 2x) - (9x - 3)
= 2x(3x - 1) - 3(3x - 1)
= (2x - 3)(3x - 1)
K MIK NHA BẠN !!!!!!!!!!
bÀI 1
bÀI 2 :
Bài 3 :
Bài 4:
5,
6,
7,
8,
9,
10,
11,
12,
13,
K MIK NHA BẠN !!!!!!!!!!
Nguyễn Quang Trung Linh Nhi : Mik cảm ơm 2 bạn nhiều nhóe ;)
tìm x biết:
a)2/3x-3/2x=5/12
b)2/5+3/5.(3x-3,7)=-53/10
c)7/9:(2+3/4x)+5/9=23/27
d)-2/3.x+1/5=3/10
e)|x|-3/4=5/3
f)|2x-1/3|+5/6=1
giúp mik vs mik đang cần gấp bn nào giải mik cũng tick nha
giải hết giúp mik các bn nhé
a; \(\dfrac{2}{3}\)\(x\) - \(\dfrac{3}{2}\)\(x\) = \(\dfrac{5}{12}\)
(\(\dfrac{2}{3}\) - \(\dfrac{3}{2}\))\(x\) = \(\dfrac{5}{12}\)
- \(\dfrac{5}{6}\)\(x\) = \(\dfrac{5}{12}\)
\(x\) = \(\dfrac{5}{12}\) : (- \(\dfrac{5}{6}\))
\(x=\) - \(\dfrac{1}{2}\)
Vậy \(x=-\dfrac{1}{2}\)
b; \(\dfrac{2}{5}\) + \(\dfrac{3}{5}\).(3\(x\) - 3,7) = \(\dfrac{-53}{10}\)
\(\dfrac{3}{5}\).(3\(x\) - 3,7) = \(\dfrac{-53}{10}\) - \(\dfrac{2}{5}\)
\(\dfrac{3}{5}\).(3\(x\) - 3,7) = - \(\dfrac{57}{10}\)
3\(x\) - 3,7 = - \(\dfrac{57}{10}\) : \(\dfrac{3}{5}\)
3\(x\) - 3,7 = - \(\dfrac{19}{2}\)
3\(x\) = - \(\dfrac{19}{2}\) + 3,7
3\(x\) = - \(\dfrac{29}{5}\)
\(x\) = - \(\dfrac{29}{5}\) : 3
\(x\) = - \(\dfrac{29}{15}\)
Vậy \(x\) \(\in\) - \(\dfrac{29}{15}\)
c; \(\dfrac{7}{9}\) : (2 + \(\dfrac{3}{4}\)\(x\)) + \(\dfrac{5}{9}\) = \(\dfrac{23}{27}\)
\(\dfrac{7}{9}\): (2 + \(\dfrac{3}{4}\)\(x\)) = \(\dfrac{23}{27}\) - \(\dfrac{5}{9}\)
\(\dfrac{7}{9}\):(2 + \(\dfrac{3}{4}\)\(x\)) = \(\dfrac{8}{27}\)
2 + \(\dfrac{3}{4}\)\(x\) = \(\dfrac{7}{9}\) : \(\dfrac{8}{27}\)
2 + \(\dfrac{3}{4}\)\(x\) = \(\dfrac{21}{8}\)
\(\dfrac{3}{4}x\) = \(\dfrac{21}{8}\) - 2
\(\dfrac{3}{4}\)\(x\) = \(\dfrac{5}{8}\)
\(x\) = \(\dfrac{5}{8}\) : \(\dfrac{3}{4}\)
\(x\) = \(\dfrac{5}{6}\)
Vậy \(x=\dfrac{5}{6}\)
(2x/5-1)chia (-5)=1/7
1/3.-6/13--9/10.-13/36
lm giúp mik
\(\frac{2x}{4}:-5=\frac{1}{7}\)
\(\frac{x}{2}=-\frac{5}{7}\)
\(x=-\frac{10}{7}\)
giúp mik với:
(x-1)^2=4
(2x+1)^3=27
(2x-1)^5=x^5
a,\(\left(x-1\right)^2=4=2^2=\left(-2\right)^2\)
\(\Rightarrow\orbr{\begin{cases}x-1=2\\x-1=-2\end{cases}\Rightarrow\orbr{\begin{cases}x=3\\x=-1\end{cases}}}\)
b,\(\left(2x+1\right)^3=27=3^3\)
\(\Rightarrow2x+1=3\Rightarrow x=1\)
c,\(\left(2x-1\right)^5=x^5\Rightarrow2x-1=x\Rightarrow x=1\)
\(a,\left(x-1\right)^2=4\)
\(\Rightarrow x-1=2\)
\(\Rightarrow x=3\)
\(b,\left(2x+1\right)^3=27\)
\(\Rightarrow2x+1=3\)
\(\Rightarrow x=1\)
\(c,\left(2x-1\right)^5=x^5\)
\(\Rightarrow2x-1=x\)
\(\Rightarrow2x-x-1=0\)
\(\Rightarrow x=1\)
Học tốt!
Giúp Mik với, tất cả bạn nào làm xong thì mik tick cho :DD
Bài 1: Tìm số hữu tỷ x biết rằng:
a) -3/2 - 2x + 3/4 = -2
b) (-2/3 . x - 3/5)(3/-2) = 2/5
c) x/2- (3x/5 - 13/5) = -(7/5 + 7/10 . x)
d) 2x - 3/3 + -3/2 = 5 - 3x/6 - 1/3
tìm số nguyên x
5/x+1+4/x+1=3/-13
-x+2+2x+3+x+1/4+2x+1/6=8/3
3/2x+1+10/4x+2-6/6x+2=12/26
giúp mình mik đang vội]
\(\dfrac{5}{x}+1+\dfrac{4}{x}+1=\dfrac{3}{-13}\\ \Rightarrow\dfrac{9}{x}+2=-\dfrac{3}{13}\\ \Rightarrow\dfrac{9}{x}=-\dfrac{59}{13}\\ \Rightarrow x=-\dfrac{207}{59}\)
a. \(\dfrac{5}{x+1}+\dfrac{4}{x+1}=\dfrac{-3}{13}\)
ĐKXĐ: x ≠ -1
⇔ \(\dfrac{65}{13\left(x+1\right)}+\dfrac{52}{13\left(x+1\right)}=\dfrac{-3\left(x+1\right)}{13\left(x+1\right)}\)
⇔ 65 + 52 = -3(x + 1)
⇔ 117 = -3x - 3
⇔ 117 + 3 = -3x
⇔ 120 = -3x
⇔ x = \(\dfrac{120}{-3}=-40\) (TM)
b. -x + 2 + 2x + 3 + x + \(\dfrac{1}{4}\) + 2x + \(\dfrac{1}{6}\) = \(\dfrac{8}{3}\)
⇔ -x + 2x + x + 2x = \(\dfrac{8}{3}-\dfrac{1}{6}-\dfrac{1}{4}-3-2\)
⇔ 4x = -2,75
⇔ x = \(\dfrac{-2,75}{4}=\dfrac{-11}{16}\)
c. \(\dfrac{3}{2x+1}+\dfrac{10}{4x+2}-\dfrac{6}{6x+2}\) = \(\dfrac{12}{26}\)
⇔ \(\dfrac{3}{2x+1}+\dfrac{10}{2\left(2x+1\right)}-\dfrac{6}{2\left(3x+1\right)}=\dfrac{12}{26}\)
⇔ \(\dfrac{312\left(3x+1\right)}{104\left(2x+1\right)\left(3x+1\right)}\) + \(\dfrac{520\left(3x+1\right)}{104\left(2x+1\right)\left(3x+1\right)}\) - \(\dfrac{312\left(2x+1\right)}{104\left(2x+1\right)\left(3x+1\right)}\)
= \(\dfrac{48\left(2x+1\right)\left(3x+1\right)}{104\left(2x+1\right)\left(3x+1\right)}\)
⇔ 312(3x +1) + 520(3x + 1) - 312(2x + 1) = 48(2x + 1)(3x + 1)
⇔ 936x + 312 + 1560x + 520 - 624x - 312 = (96x + 48)(3x + 1)
⇔ 936x + 312 + 1560x + 520 - 624x - 312 = 288x2 + 96x + 144x + 48
⇔ 936x + 1560x - 624x - 96x - 144x - 288x2 = 48 - 312 - 520 + 312
⇔ 1632x - 288x2 = -472
⇔ -288x2 + 1632x + 472 = 0 (Tự giải tiếp, dùng phương pháp tách hạng tử)
⇔ x = 5,942459684 \(\approx\) 6
c: Ta có: \(\dfrac{3}{2x+1}+\dfrac{10}{4x+2}-\dfrac{6}{6x+3}=\dfrac{12}{26}\)
\(\Leftrightarrow\dfrac{3}{2x+1}+\dfrac{5}{2x+1}-\dfrac{2}{2x+1}=\dfrac{6}{13}\)
\(\Leftrightarrow2x+1=13\)
hay x=6
Tim X
3) -12 + (2x – 9) + x= 0
4) 11 + (15 - x) = 1
5) 4 - (27 - 3) = x - (13 - 4)
6) 8 - (x - 10) = 23 - (- 4 +12)
7) 105 – 5(10 – 5x) = -20
8) (x -1)(8-2x)(3x+123) = 0
9) (x2 - 25)(x+ 10) = 0
10) x(x2+5) =
3) \(-12+2x-9+x=0\\ -21+3x=0\\ 3x=21\\ x=7\)
4)
\(11+\left(15-x\right)=1\)
\(15-x=1-11\)
\(15-x=-10\)
\(x=15-\left(-10\right)\)
\(x=25\)
5)
\(4-\left(27-3\right)=x-\left(13-4\right)\)
\(4-24=x-9\)
\(x-9=-20\)
\(x=-20+9\)
\(x=-11\)
\(3.-12+\left(2x-9\right)+x=0.\)
\(\Leftrightarrow-12+2x-9+x=0.\Leftrightarrow3x=21.\Leftrightarrow x=7.\)
Vậy \(x=7.\)
\(4.11+\left(15-x\right)=1.\Leftrightarrow11+15-x=1.\Leftrightarrow26-x=1.\Leftrightarrow x=25.\)
Vậy \(x=25.\)
\(5.4-\left(27-3\right)=x-\left(13-4\right).\Leftrightarrow4-24=x-9.\Leftrightarrow-20=x-9.\Leftrightarrow x=-11.\)
Vậy \(x=-11.\)
\(6.8-\left(x-10\right)=23-\left(-4+12\right).\Leftrightarrow8-x+10=23-8.\Leftrightarrow18-x=15.\Leftrightarrow x=3.\)
Vậy \(x=3.\)
\(7.105-5\left(10-5x\right)=-20.\Leftrightarrow105-50+25x=-20.\Leftrightarrow25x=-75.\Leftrightarrow x=-3.\)
Vậy \(x=-3.\)
\(8.\left(x-1\right)\left(8-2x\right)\left(3x+123\right)=0.\)
\(\Leftrightarrow\left[{}\begin{matrix}x-1=0.\\8-2x=0.\\3x+123=0.\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=1.\\x=4.\\x=-41.\end{matrix}\right.\)
Vậy \(x\in\left\{1;4;-41\right\}.\)
\(9.\left(x^2-25\right)\left(x+10\right)=0.\)
\(\Leftrightarrow\left(x-5\right)\left(x+5\right)\left(x+10\right)=0.\)
\(\Leftrightarrow\left[{}\begin{matrix}x-5=0.\\x+5=0.\\x+10=0.\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=5.\\x=-5.\\x=-10.\end{matrix}\right.\)
Vậy \(x\in\left\{5;-5;-10\right\}.\)
\(10.x\left(x^2+5\right)=0.\Leftrightarrow x=0.\)