=>3/4 x (8/9+2/3)=3/4 x 2/9 =6/36=1/6

Giúp mình nhé 

bạn đăng tách cho mn cùng giúp nhé 

Bài 1 : 

a, \(\Leftrightarrow11-x=12-8x\Leftrightarrow7x=1\Leftrightarrow x=\dfrac{1}{7}\)

b, \(\Leftrightarrow2x\left(x^2+4x+4\right)-8x^2=2\left(x^3-8\right)\)

\(\Leftrightarrow2x^3+8x^2+8x-8x^2=2x^3-16\Leftrightarrow x=-2\)

c, \(\Leftrightarrow3-2x=-x-4\Leftrightarrow x=7\)

d, \(\Leftrightarrow x^3-6x^2+12x-8+9x^2-1=x^3+3x^2+3x+1\)

\(\Leftrightarrow3x^2+12x-9=3x^2+3x+1\Leftrightarrow x=\dfrac{10}{9}\)

e, \(\Leftrightarrow2x^2-x-3=2x^2+9x-5\Leftrightarrow x=5\)

f, \(\Leftrightarrow x^3-3x^2+3x-1-x^3-2x^2-x=10x-5x^2-11x-22\)

\(\Leftrightarrow-5x^2+2x-1=-5x^2-x-22\Leftrightarrow3x=-21\Leftrightarrow x=-7\)

Cảm ơn bạn nhiều ạ 

\(\left\{{}\begin{matrix}2x+3y=-2\\3x-2y=-3\end{matrix}\right.\) ⇔ \(\left\{{}\begin{matrix}6x+9y=-6\\6x-4y=-6\end{matrix}\right.\)⇔ \(\left\{{}\begin{matrix}14y=0\\2x+3y=-2\end{matrix}\right.\)⇔\(\left\{{}\begin{matrix}y=0\\x=-1\end{matrix}\right.\)

\(3^2A=3^2.\left(1+3^2+3^4+...+3^{100}\right)\)

\(3^2A=3^2+3^4+...+3^{102}\)

\(3^2A-A=\left(3^2+3^4+...+3^{102}\right)-\left(1+3^2+....+3^{100}\right)\)

\(8A=3^{102}-1\)

\(A=\frac{3^{102}-1}{8}\)

bài B tương tự nha 

cậu giải thích giùm mình đoạn này với P(x)=x^7-(x+1)x^6+(x+1)x^5-(x+1)x^4+(x+1)x^3-(x+1)x^2+(x+1)x+15

P(x)=x^7-x^7-x^6+x^6+x^5-x^5-x^4+x^4+x^3-x^3-x^2+x^2+x+15

P(x)=x+15=79+15=94

hay giai giup mk may phan nay nhe

cmr cac bieu thuc sau ko phu thuoc vao x:

c)C=x(x^3+x^2-3x-2)-(x^2-2)(x^2+x-1)

e)E=(x+1)(x^2-x+1)-(x-1)(x^2+x+1)

tinh gia tri cua da thuc

b)Q(x)=x^14-10x^13=10x^12-10x^11+...+10x^2-10x+10   voi x=9

c)R(x)=x^4-17x^3+17x^2_17x+20   või=16

d)S(x)=x^10-13x^9+13x^8-13X^7+...+13x^2-13x+10     voi 12

bạn ghi + - x : nhá

Bài 1: 

a, \(\dfrac{-x-2}{3}\) = - \(\dfrac{6}{7}\)

      - \(x\) - 2 = - \(\dfrac{18}{7}\)

         \(x\)      = - 2 + \(\dfrac{18}{7}\)

         \(x\)      = - \(\dfrac{4}{7}\)

Bài b,  \(\dfrac{4}{7-x}\) = \(\dfrac{1}{3}\)

            12 = 7 - \(x\)

            \(x\)  = 7 - 12 

            \(x\)  = -5