\(A=\frac{24.47-23}{24+27-23}.\frac{9-\frac{9}{7}+\frac{9}{11}+\frac{9}{1001}-\frac{9}{11}}{\frac{2}{1001}-\frac{2}{13}-\frac{2}{7}+\frac{2}{11}+2}\)

co sai de ko bn

\(\Rightarrow\)

Mình nhầm đề câu A tí nha !

\(A=\frac{24\cdot47-23}{24+47-23}\cdot\frac{9-\frac{9}{7}+\frac{9}{11}+\frac{9}{1001}-\frac{9}{13}}{\frac{2}{1001}-\frac{2}{13}-\frac{2}{7}+\frac{2}{11}+2}\)

Ai làm nhanh 3 k !

So HSG hoc ki I bang:3/10 hoc sinh ca lop

So HSG cuoi nam bang 2/5 h/s ca lop

Phan so chi 4 hoc sinh la:

\(\frac{2}{5}-\frac{3}{10}=\frac{1}{10}\)

So HSG 6A la:

\(4:\frac{1}{10}=40\)(hoc sinh)

HTDT

\(3\frac{1}{3}x+16\frac{3}{4}=-13,25\)

\(\Leftrightarrow\frac{3\times3+1}{3}x+\frac{16\times4+3}{4}=-13,25\)

\(\Leftrightarrow\frac{9+1}{3}x+\frac{64+3}{4}=-13,25\)

\(\Leftrightarrow\frac{10}{3}x+\frac{67}{4}=-13,25\)

\(\Leftrightarrow\frac{10}{3}x+16,75=-13,25\)

\(\Leftrightarrow\frac{10}{3}x=-13,25-16,75\)

\(\Leftrightarrow\frac{10}{3}x=-30\)

\(\Leftrightarrow x=-30\div\frac{10}{3}\)

\(\Leftrightarrow x=\frac{-30}{1}\times\frac{3}{10}\)

\(\Leftrightarrow x=\frac{-90}{10}\)

\(\Leftrightarrow x=-9\)

b,Ta có 

\(\frac{2010}{2011}>\frac{2010}{2011+2012+2013}\)

\(\frac{2011}{2012}>\frac{2011}{2011+2012+2013}\)

\(\frac{2012}{2013}>\frac{2012}{2011+2012+2013}\)

\(\Rightarrow P>Q\)

\(A=\frac{-10}{20}+\frac{-10}{30}+\frac{-10}{42}+\frac{-10}{56}+\frac{-10}{72}+\frac{-10}{90}+\frac{-10}{110}\)

\(=-10\left(\frac{1}{20}+\frac{1}{30}+\frac{1}{42}+\frac{1}{56}+\frac{1}{72}+\frac{1}{90}+\frac{1}{110}\right)\)

\(=-10\left(\frac{1}{4.5}+\frac{1}{5.6}+\frac{1}{6.7}+\frac{1}{7.8}+\frac{1}{8.9}+\frac{1}{9.10}+\frac{1}{10.11}\right)\)

\(=-10\left(\frac{1}{4}-\frac{1}{11}\right)\)

\(=\frac{-35}{22}\)

\(x-23=-35-x\)

\(\Leftrightarrow x-23+x=-35\)

\(\Leftrightarrow\left(x+x\right)-23=-35\)

\(\Leftrightarrow2x-23=-35\)

\(\Leftrightarrow2x=-35+23\)

\(\Leftrightarrow2x=-12\)

\(\Leftrightarrow x=-12\div2\)

\(\Leftrightarrow x=6\)

\(\text{Vậy }x=6\)

\(x-23=-35-x\)

\(\Rightarrow x+x=-35+23\)

\(\Rightarrow2x=-12\)

\(\Rightarrow x=-6\)

                                            Giải

\(\frac{a}{b}+\frac{a}{c}=\frac{ac+ab}{bc}=\frac{a\left(b+c\right)}{bc}\)                      ( 1 )

\(\frac{a}{b}.\frac{a}{c}=\frac{a.a}{bc}\)                                                          ( 2 )

Từ ( 1 ) và ( 2 ) suy ra \(\frac{a}{b}+\frac{a}{c}=\frac{a}{b}.\frac{a}{c}\Leftrightarrow\frac{a\left(b+c\right)}{bc}=\frac{a^2}{bc}\)

\(\Leftrightarrow a\left(b+c\right)=a^2\)

\(\Leftrightarrow b+c=a\)

Vậy hệ thức b + c = a để tổng hai phân số bằng tích của chúng.

\(1023^{1024}=\left(1023^4\right)^{256}=\left(....1\right)^{256}=\left(.....6\right)\)

\(8^{1975}=8^3.8^{1972}=512.\left(8^4\right)^{493}=512.\left(4096\right)^{493}=512.\left(.....6\right)=\left(.....2\right)\)

\(2^{4n-5}=\left(2^4\right)^n:2^5=\left(16\right)^n:32=\left(....6\right):32=\left(....8\right)\)

\(2^{4n+2}+1=\left(2^4\right)^5.2^2+1=\left(16\right)^5.4+1=\left(....6\right).4+1=\left(...4\right)+1=\left(.....5\right)\)

P/s: Hoq chắc ạ :))))

1 thì vẫn bằng 1 thui

sao đây lại là toán lớp 6 j bạn 1

=2016

vì ở trên có số 2015 nên mình nghĩ vậy nếu sai thì bn đừng ném đá mình nhé

a.={75+(-75)}+{15+(-32)}+-55

=0+-17+-55

=0+{(-17)+(-55)

=0+-75

=-75

b. =(35+35)+(65-65)+(24-24)

=70+0+0

=70

không biết đúng hay sai mong mấy bạn thông cảm vì mình cũng không chắc chắn !

2) -3(5⁰ - x)³ = 81

=> (1 - x)³ = 81 : (-3)

=> (1 - x)³ = -27

=> (1 - x)³ = (-3)³

=> 1 - x = -3

=> x = 1  + 3

=> x  = 4

2. suy ra (1-x )³ =81: (-3)=-27 =(-3)³

suy ra 1-x=-3 

     x=4