\(\Leftrightarrow\frac{4x^2}{5}\times\frac{2x-3}{6}-\frac{3x-10}{15}\times\frac{4x^2+3}{3}=\frac{22x^2}{45}\)

\(\Leftrightarrow\frac{4x^2\left(2x-3\right)}{30}-\frac{\left(3x-10\right)\left(4x^2+3\right)}{45}=\frac{22x^2}{45}\)

\(\Leftrightarrow\frac{12x^2\left(2x-3\right)}{90}-\frac{2\left(3x-10\right)\left(4x^2+3\right)}{90}=\frac{44x^2}{90}\)

\(\Leftrightarrow12x^2\left(2x-3\right)-2\left(3x-10\right)\left(4x^2+3\right)=44x^2\)

\(\Leftrightarrow24x^2-36x^2-2\left(12x^3+9x-40x^2-30\right)=44x^2\)

\(\Leftrightarrow24x^2-36x^2-24x^3-18x+80x^2+60=44x^2\)

\(\Leftrightarrow24x^3-36x^2-24x^3-18x+80x^2-44x^2=-60\)

\(\Leftrightarrow\left(24x^3-24x^3\right)+\left(-36x^2+80x^2-44x^2\right)-18x=-60\)

\(\Leftrightarrow-18x=-60\)

\(\Leftrightarrow x=\frac{-60}{-18}\)

\(\Leftrightarrow x=\frac{10}{3}\)

Mình đang cần gắp 

bạn còn

\(\frac{4}{7}\times x=\frac{1}{5}+\frac{2}{3}\)

\(\frac{4}{7}x=\frac{13}{15}\)

\(\Rightarrow x=\frac{91}{60}\)

các bài còn lại tương tự nha 

mấy cái này dễ mà toán tìm x này là cơ bản!!

67865785685685785785774677567568568

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

\(\frac{4}{7}\times x=\frac{2}{3}+\frac{1}{5}\)

\(\frac{4}{7}\times x=\frac{13}{15}\)

\(x=\frac{13}{15}\div\frac{4}{7}\)

\(x=\frac{91}{60}\)

Mình làm cách lớp 6 nha bạn, cách lớp 4 mình không biết.
\(\frac{1}{2}.x+\frac{1}{5}.x=\frac{2}{5}\)
\(\Rightarrow x.\left(\frac{1}{2}+\frac{1}{5}\right)=\frac{2}{5}\)
\(\Rightarrow x.\frac{7}{10}=\frac{2}{5}\)
Giờ thành tìm x rồi!
\(x=\frac{7.5}{2.10}\)
\(x=1\frac{3}{4}\)
Xong!

\(\frac{1}{2}\times x+\frac{1}{5}\times x=\frac{2}{5}\)

   \(x\times\left(\frac{1}{2}+\frac{1}{5}\right)=\frac{2}{5}\)

                  \(x\times\frac{7}{10}=\frac{2}{5}\)

                              \(x=\frac{2}{5}:\frac{7}{10}\)

                              \(x=\frac{4}{7}\)

\(\frac{1}{2}\times x+\frac{1}{5}\times x=\frac{2}{5}\)

\(\Rightarrow\left(\frac{1}{2}+\frac{1}{5}\right)\times x=\frac{2}{5}\)

\(\frac{7}{10}\times x=\frac{2}{5}\)

\(x=\frac{2}{5}:\frac{7}{10}\)

\(x=\frac{4}{7}\)

\(x\times\frac{1}{5}+\frac{1}{5}\times x-x\times\frac{1}{5}=\frac{1}{5}\)

           \(x\times\left(\frac{1}{5}+\frac{1}{5}-\frac{1}{5}\right)=\frac{1}{5}\)

                                      \(x\times\frac{1}{5}=\frac{1}{5}\)

                                                \(x=\frac{1}{5}:\frac{1}{5}\)

                                                 \(x=1\)

Vậy x = 1

ủng hộ mik nha các bn

chúc các bn giáng sinh vui vẻ

x × 1/5 + 1/5 × x − x × 1/5 = 1/5

 x × (1/5 + 1/5 − 1/5) = 1/5

 x × 1/5 = 1/5

 x = 1/5 : 1/5

 x = 1

                         Mery christmas

Xx1/5+1/5xX-Xx1/5=1/5

Xx(1/5+1/5-1/5)=1/5

Xx1/5=1/5

X=1/5:1/5

X=1

đúng!100%

(^-^)

1/2 . 1/3 . 1/4 . 1/5 . 1/6 . ( x - 1,010 ) = 1/360 - 1/720

1/2 . 1/3 . 1/4 . 1/5 . 1/6 . ( x - 1,010) = 1/720

( x - 1,010 ) . 1/2 . 1/3 . 1/4 . 1/5 . 1/6 = 1/720

( x - 1,010 ) . 1/720 = 1/720

x - 1,010 = 1/720 : 1/720

x - 1,010 = 1

          x  = 1 + 1,010

          x  = 2,01

\(a,\)\(-\frac{3}{5}\cdot x=\frac{1}{4}+0,75\)

\(-\frac{3}{5}\cdot x=\frac{1}{4}+\frac{3}{4}=\frac{4}{4}=1\)

\(x=1\div\left(-\frac{3}{5}\right)\)

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

\(b,\)\(\left(\frac{1}{7}-\frac{1}{3}\right)\cdot x=\frac{28}{5}\times\left(\frac{1}{4}-\frac{1}{7}\right)\)

\(\left(\frac{3}{21}-\frac{7}{21}\right)\cdot x=\frac{28}{5}\cdot\left(\frac{7}{28}-\frac{4}{28}\right)\)

\(-\frac{4}{21}\cdot x=\frac{28}{5}\cdot\frac{3}{28}\)

\(-\frac{4}{21}\cdot x=\frac{3}{5}\)

\(x=\frac{3}{5}\div\left(-\frac{4}{21}\right)\)

\(x=-\frac{63}{20}\)

\(c,\)\(\frac{5}{7}\cdot x=\frac{9}{8}-0,125\)

\(\frac{5}{7}\cdot x=\frac{9}{8}-\frac{1}{8}\)

\(\frac{5}{7}\cdot x=1\)

\(x=1\div\frac{5}{7}\)

\(x=\frac{7}{5}\)

\(d,\)\(\left(\frac{2}{11}+\frac{1}{3}\right)\cdot x=\left(\frac{1}{7}-\frac{1}{8}\right)\cdot36\)

\(\left(\frac{6}{33}+\frac{11}{33}\right)\cdot x=\left(\frac{8}{56}-\frac{7}{56}\right)\cdot36\)

\(\frac{17}{33}\cdot x=\frac{1}{56}\cdot36\)

\(\frac{17}{33}\cdot x=\frac{9}{14}\)

\(x=\frac{9}{14}\div\frac{17}{33}\)

\(x=\frac{9}{14}\cdot\frac{33}{17}=\frac{297}{238}\)

a)\(\frac{3}{5}\times x=1\)                                        

\(x=1\div\frac{3}{5}\)

\(x=\frac{5}{3}\)

Mình chỉ làm duoc câu a thôi 

a) Thiếu đề (hoặc sai)

b) x đâu?

c)\(3x-1=x+2\)

\(\Rightarrow3x-x=2+1\)

\(\Rightarrow2x=3\)

\(\Rightarrow x=\frac{3}{2}\)

c) \(\frac{x+2}{5}=\frac{2-3x}{3}\)

\(\Rightarrow3.\left(x+2\right)=5.\left(2-3x\right)\)

\(\Rightarrow3x+6=10-15x\)

\(\Rightarrow3x+15x=10-6\)

\(\Rightarrow18x=4\)

\(\Rightarrow x=\frac{4}{18}=\frac{2}{9}\)

câu 1 là \(x\times\left(4.6+\frac{3}{5}\right)=7.2-8.15\)

câu 2 là \(42+\frac{3}{7}.\left[3\times x-1=12\right]\)

a)\(x.\left(4,6+\frac{3}{5}\right)=7,2-8,15\)

\(\Rightarrow\left(\frac{23}{5}+\frac{3}{5}\right).x=-0,95\)

\(\Rightarrow\frac{26}{5}.x=\frac{-19}{20}\)

\(\Rightarrow x=\frac{-19}{20}:\frac{26}{5}\)

\(\Rightarrow x=\frac{-19}{104}\)

Mà \(4.6\)là\(4,6\)hay \(4\times6?\)nếu sai tớ làm lại

b) Ngoặc sai rồi

\(42+\frac{3}{7}.\left(3x-1\right)=12\)

\(\Rightarrow\frac{3}{7}.\left(3x-1\right)=12-42\)

\(\Rightarrow\frac{3}{7}.\left(3x-1\right)=-30\)

\(\Rightarrow3x-1=-30:\frac{3}{7}\)

\(\Rightarrow3x-1=\frac{-10}{7}\)

\(\Rightarrow3x=\frac{-10}{7}+1\)

\(\Rightarrow3x=\frac{-10+7}{7}=\frac{-3}{7}\)

\(\Rightarrow x=\frac{-3}{7}:3=\frac{-1}{7}\)

Lưu ý nhé viết dấu nhân thì viết \("."\)một thể, \("\times"\)một thể. Còn dâu phảy của số thập phân thì viết ",'' nhé