A= -5/1/7+32/5=0.22857142857142286

B= -2/1/3-1/2/7=119047619047619

a) 973

b) 1011101

c) 58

e) 19039

f) 11111101

g) 43

k) 1EA9

l) 401

m) 111001101011

Ta có \(M=\frac{\frac{3}{5}+\frac{3}{7}-\frac{3}{11}}{\frac{4}{5}+\frac{4}{7}-\frac{4}{11}}=\frac{3\left(\frac{1}{5}+\frac{1}{7}-\frac{1}{11}\right)}{4\left(\frac{1}{5}+\frac{1}{7}-\frac{1}{11}\right)}=\frac{3}{4}\)

tử=3(1/5+1/7-1/11)

mẫu=4(1/5+1/7-1/11)

M=3/4

\(M=\frac{\frac{3}{5}+\frac{3}{7}-\frac{3}{11}}{\frac{4}{5}+\frac{4}{7}-\frac{4}{11}}\)

\(\Rightarrow M=\frac{3\times\left(\frac{1}{5}+\frac{1}{7}+\frac{1}{11}\right)}{4\times\left(\frac{1}{5}+\frac{1}{7}-\frac{1}{11}\right)}\)

\(\Rightarrow M=\frac{3}{4}\)

\(\dfrac{5}{3}+\dfrac{7}{5}+\dfrac{20}{7}+\dfrac{19}{2}=\dfrac{5.3}{3.70}+\dfrac{7.42}{5.42}+\dfrac{20.30}{7.30}+\dfrac{19.105}{2.105}\)

\(=\dfrac{15}{210}+\dfrac{294}{210}+\dfrac{600}{210}+\dfrac{1995}{210}=\dfrac{2904}{210}=\dfrac{484}{35}\)

tính nhanh hay j

620m^2 

1/4:x=2/3-3/4

1/4:x=1/12

x=1/4:1/12

x=1/4.12

x=3\(\in\)Q (thỏa mãn)

Vậy x=3

3/4 + 1/4 : x = 2/3

=> 1/4 : x  = 2/3 - 3 / 4 = -1/12

=> x = 1/4 : -1/12

=> x = -3.

Vậy x ( số cần tìm ) có giá trị là :-3.

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

        \(\frac{1}{4}:x\) = \(\frac{2}{3}\) -\(\frac{3}{4}\)

        \(\frac{1}{4}:x=\) \(\frac{-1}{12}\)

              \(x\) = \(\frac{1}{4}:\frac{-1}{12}\)

              \(x=-3\)

                                   Chúc bạn học tốt 

8 + 9 + 15 : 5 × 3 = 8 + 9 + 3 × 3 = 8 + 9 + 9 = 17 + 9 = 26.

\(8+9+15:5\times3\)

\(=8+9+3\times3\)

\(=8+9+9\)

\(=26\)

tíc mình nha

   8 + 9 + 15 : 5 x 3

= 8 + 9 +     3   x 3 ( làm theo biểu thức : nhân , chia trước cộng , trừ sau )

= 8 + 9 +          9

=   17   +          9 

=        26

k nha ^_-