co ai giai dc ko cau 60 % .....

$\textbf{Ta có:}$

$A=\dfrac{-5^2-5\cdot3^2}{5^3+5^2\cdot3^2}$

$=\dfrac{-25-45}{125+225}$

$=\dfrac{-70}{350}$

$=-\dfrac15.$

Và

$B=\dfrac{2^{12}\cdot3^{10}+6^9\cdot120}{2^{12}\cdot3^{12}-2^{11}\cdot3^{11}}$

$=\dfrac{2^{12}3^{10}+2^{12}3^{10}\cdot5}{2^{11}3^{11}(2\cdot3-1)}$

$=\dfrac{2^{12}3^{10}(1+5)}{2^{11}3^{11}\cdot5}$

$=\dfrac{2^{12}3^{10}\cdot6}{2^{11}3^{11}\cdot5}$

$=\dfrac{2^2}{5}$

$=\dfrac45.$

=> $M=B-A$$=\dfrac45-\left(-\dfrac15\right)$

$=\dfrac55$$=1.$

Ta có: \(\frac{-1}{9}\cdot\frac{-3}{5}-\frac56\cdot\frac{3}{-5}+\frac{-5}{2}\cdot\frac35\)

\(=\frac19\cdot\frac35+\frac56\cdot\frac35+\frac35\cdot\frac{-5}{2}\)

\(=\frac35\left(\frac19+\frac56-\frac52\right)\)

\(=\frac35\left(\frac{2}{18}+\frac{15}{18}-\frac{45}{18}\right)=\frac35\cdot\frac{2-30}{18}=\frac35\cdot\frac{-28}{18}=\frac35\cdot\frac{-14}{9}=\frac{-42}{45}=-\frac{14}{15}\)

bằng 19/44 nhá

tớ tính mãi mới ra

.......................................

19/44

a)x-5/7=-2/3+1/3
   x-5/7=-1/3
        x=-1/3+5/7
        x=8/21
b)1/3x+5/7=-9/4
x+5/7=-9/4:1/3
x+5/7=-27/4
x=-27/4-5/7
x=-209/28

a: x-5/7=-2/3+1/3

=>x-5/7=-1/3

=>x=-1/3+5/7=8/21

b: 1/3*x+5/7=-9/4

=>x*1/3=-9/4-5/7=-83/28

=>x=-83/28:1/3=-83/28*3=-249/28

c: 1/6x:1/4=-1/24

=>1/6x=-1/96

=>x=-1/16

-3/4+3/4* (x-1/2)+1/6=-1

=0*(x-1/2)=-7/6

nên ko tìm đc x

Ta có: \(3,25\cdot\frac{-4}{13}\cdot\left(-\frac67\right)\cdot\left(\frac23\right)^4\)

\(=-\frac{13}{13}\cdot\frac{-6}{7}\cdot\frac{16}{81}\)

\(=\frac67\cdot\frac{16}{81}=\frac{6}{81}\cdot\frac{16}{7}=\frac{16}{7}\cdot\frac{2}{27}=\frac{32}{189}\)

=20 bn nhé

dễ, nhưng phai giai dc câu nay  60% nhan x cong 2 phan 3 = 1 phan 3 nhan 6va 1 phan 3

dễ mà