a, x + \(2\frac{3}{4}\)= \(5\frac{2}{3}\)

= x + \(\frac{11}{4}\)= \(\frac{17}{3}\)

x = \(\frac{17}{3}\)- \(\frac{11}{4}\)

x = \(\frac{35}{12}\)

b , x - \(1\frac{4}{5}\)= \(3\frac{2}{7}\)

 = x - \(\frac{9}{5}\)= \(\frac{23}{7}\)

x = \(\frac{23}{7}\)+ \(\frac{9}{5}\)

x = \(\frac{178}{35}\)

c , x * \(\frac{31}{2}\)= \(4\frac{3}{4}\)

= x * \(\frac{31}{2}\)=\(\frac{19}{4}\)

x = \(\frac{19}{4}\): \(\frac{31}{2}\)

x = \(\frac{38}{124}\)= \(\frac{19}{64}\)

d , x : 2 2/? = 4 1/3 câu d thiếu nha bạn 

\(\frac{x}{3\frac{1}{2}.2\frac{2}{3}}=\frac{9}{56}\Rightarrow\frac{x}{\frac{7}{2}.\frac{8}{3}}=\frac{9}{56}\Rightarrow x=\frac{9}{56}.\frac{28}{3}=\frac{3}{2}\)

\(x:\left(3\frac{1}{2}.2\frac{2}{3}\right)=\frac{9}{56}\)

\(x:\left(\frac{7}{2}.\frac{8}{3}\right)=\frac{9}{56}\)

\(x:\left(\frac{7.4}{3}\right)=\frac{9}{56}\)

\(x.\frac{3}{28}=\frac{9}{56}\)

\(x=\frac{9}{56}.\frac{28}{3}=\frac{3}{2}\)

Vậy \(x=\frac{3}{2}\)

a ) 5^x-2 - 3² = 2⁴ - ( 2⁸ . 2⁴ - 2¹⁰ . 2² )

5^x-2 - 9 = 16 - ( 256 . 16 - 1024 . 4 ) 

5^x-2 - 9 = 16 - ( 4096 - 4096 ) = 16 - 0

5^x-2 = 16 + 9 = 25  nhưng\(\sqrt{25}=5^2\)x = 2 + 2 = 4

b ) b ) 697 : [( 15 x + 364 ) : x ] = 17

mình ko hiểu đề cho lắm

a) \(x\left(2x+1\right)-x^2\left(x+2\right)+\left(x^3-x+3\right)=3\)

\(\Leftrightarrow2x^2+x-x^3-2x^2+x^3-x+3=3\)

\(\Leftrightarrow3=3\)( Luôn đúng với mọi x )

Vậy phương trình nghiệm đúng với mọi x

b) \(4\left(x-6\right)-x^2\left(2+3x\right)+x\left(5x-4\right)+3x\left(x-1\right)=12x+12\)

\(\Leftrightarrow4x-24-2x^2-3x^3+5x^2-4x+3x^2-3x=12x+12\)

\(\Leftrightarrow-3x^3+6x^2-3x-24=12x+12\)

\(\Leftrightarrow-3x^3+6x^2-3x-24-12x-12=0\)

\(\Leftrightarrow-3x^3+6x^2-15x-36=0\)

Đến đây xem lại đề bạn nhớ :D Tìm thì tìm được nhưng thấy nó sai sai kiểu gì í

c) \(\left(3x+1\right)\left(x-2\right)=\left(2-x\right)\left(-3x-5\right)\)

\(\Leftrightarrow3x\left(x-2\right)+1\left(x-2\right)=2\left(-3x-5\right)-x\left(-3x-5\right)\)

\(\Leftrightarrow3x^2-6x+x-2=-6x-10+3x^2+5x\)

\(\Leftrightarrow3x^2-6x+x+6x-3x^2-5x=-10+2\)

\(\Leftrightarrow-4x=-8\)

\(\Leftrightarrow x=2\)

d) \(\left(x+3\right)\left(x+5\right)-x\left(x+7\right)=2x+8\)

\(\Leftrightarrow x\left(x+5\right)+3\left(x+5\right)-x\left(x+7\right)=2x+8\)

\(\Leftrightarrow x^2+5x+3x+15-x^2-7x=2x+8\)

\(\Leftrightarrow x^2+5x+3x-x^2-7x-2x=8-15\)

\(\Leftrightarrow-x=-7\)

\(\Leftrightarrow x=7\)

a, \(x\left(2x-1\right)-x^2\left(x+2\right)+\left(x^3-x+3\right)=3\)

\(\Leftrightarrow2x^2-x-x^3-2x^2+x^3-x+3=3\)

\(\Leftrightarrow-2x=0\Leftrightarrow x=0\)

b, \(4\left(x-6\right)-x^2\left(2+3x\right)+x\left(5x-4\right)+3x\left(x-1\right)=12x+12\)

\(\Leftrightarrow4x-24-2x^2-3x^3+5x^2-4x+3x^2-3x=12x+12\)

\(\Leftrightarrow-3x-24+6x^2-3x^3=12x+12\)

\(\Leftrightarrow-15x-36+6x^2-3x^3=0\)

Lớp 8 chưa hc vô tỉ đâu ... vô nghiệm 

c, \(\left(3x+1\right)\left(x-2\right)=\left(2-x\right)\left(-3x-5\right)\)

\(\Leftrightarrow3x^2-5x-2=-x-10+3x^2\)

\(\Leftrightarrow-4x+8=0\Leftrightarrow x=2\)

d, \(\left(x+3\right)\left(x+5\right)-x\left(x+7\right)=2x+8\)

\(\Leftrightarrow x^2+8x+15-x^2-7x=2x+8\)

\(\Leftrightarrow x+15=2x+8\Leftrightarrow-x+7=0\Leftrightarrow x=7\)

lam nhanh giup minh nha minh se tick cho

nhiều bài quá mình chỉ làm được bài 1,3,4,5

bài 2 mình đang suy nghĩ

bạn có thể vào để hỏi bài !

C= -(x+2)²-(2x+y+1)²+2016

Tinh gia tri lon nhat hoac nho nhat

A) \(\frac{3}{2}\times\frac{4}{5}-x=\frac{2}{3}\)

    \(\frac{6}{5}-x=\frac{2}{3}\)

                \(x=\frac{6}{5}-\frac{2}{3}\)

                \(x=\frac{8}{15}\)

b) \(x\times3\frac{1}{3}=3\frac{1}{3}\div4\frac{1}{4}\)

    \(x\times\frac{10}{3}=\frac{10}{3}\div\frac{17}{4}\)

    \(x\times\frac{10}{3}=\frac{40}{51}\)

    \(x=\frac{40}{51}\div\frac{10}{3}\)

    \(x=\frac{4}{17}\)

c) \(x+\frac{1}{2}\times\frac{1}{3}=\frac{3}{4}\)

   \(x+\frac{1}{6}=\frac{3}{4}\)

  \(x=\frac{3}{4}-\frac{1}{6}\)

  \(x=\frac{7}{12}\)

~ HOK TỐT ~

a ) 3/2 x 4/5 - x = 2/3

     6/5 - x = 2/3

           - x = 2/3 - 6/5

           - x = 10/15 - 18/15

           - x = -8/15

             x = 8/15

b ) x * 31/3 = 31/3 : 41/4

     x * 31/3 = 124/123

               x = 124/123 : 31/3

               x = 4/41

c ) x + 1/2 x 1/3 = 3/4

     x + 1/6 = 3/4

              x = 3/4 - 1/6

              x = 9/12 - 2/12

              x = 7/12