\(\text{Xét công thức tổng quát }:x^4+\frac{1}{4}=\left(x^4+2.x^2.\frac{1}{2}+\frac{1}{4}\right)-x^2\)

\(=\left(x^2+\frac{1}{2}\right)^2-x^2=\left(x^2-x+\frac{1}{2}\right)\left(x^2+x+\frac{1}{2}\right)\)

Áp dụng vào B ta đc:

\(B=\frac{\left(1^4+\frac{1}{4}\right)\left(3^4+\frac{1}{4}\right)...\left(11^4+\frac{1}{4}\right)}{\left(2^4+\frac{1}{4}\right)\left(4^4+\frac{1}{4}\right)...\left(12^4+\frac{1}{4}\right)}\)

\(=\frac{\left(1^2-1+\frac{1}{2}\right)\left(1^2+1+\frac{1}{2}\right)\left(3^2-3+\frac{1}{2}\right)\left(3^2+3+\frac{1}{2}\right)...\left(11^2-11+\frac{1}{2}\right)\left(11^2+11+\frac{1}{2}\right)}{\left(2^2-2+\frac{1}{2}\right)\left(2^2+2+\frac{1}{2}\right)\left(4^2-4+\frac{1}{2}\right)\left(4^2+4+\frac{1}{2}\right)...\left(12^2-12+\frac{1}{2}\right)\left(12^2+12+\frac{1}{2}\right)}\)

\(=\frac{\frac{1}{2}\left(2+\frac{1}{2}\right)\left(6+\frac{1}{2}\right)\left(12+\frac{1}{2}\right)...\left(110+\frac{1}{2}\right)\left(122+\frac{1}{2}\right)}{\left(2+\frac{1}{2}\right)\left(6+\frac{1}{2}\right)\left(12+\frac{1}{2}\right)\left(20+\frac{1}{2}\right)...\left(132+\frac{1}{2}\right)\left(156+\frac{1}{2}\right)}\)

\(=\frac{\frac{1}{2}\left(122+\frac{1}{2}\right)}{\left(132+\frac{1}{2}\right)\left(156+\frac{1}{2}\right)}=\frac{49}{16589}\)

ko biết có đúng ko!! hình như còn 1 cách là nhân 1 đa thức với 16 nữa thì phải lâu ko động đến bạn thử xem đc ko nhé

Lời giải:

$\sqrt{0,169}+\sqrt{0,25}-\sqrt{(-11)^2}$

$=\sqrt{0,13^2.10}+\sqrt{0,5^2}-\sqrt{(-11)^2}$

$=|0,13|\sqrt{10}+|0,5|-|-11|$

$=0,13\sqrt{10}+0,5-11=0,13\sqrt{10}-10,5$

\(1,\\ a,=\left(\dfrac{1}{4}\right)^3\cdot32=\dfrac{1}{64}\cdot32=\dfrac{1}{2}\\ b,=\left(\dfrac{1}{8}\right)^3\cdot512=\dfrac{1}{512}\cdot512=1\\ c,=\dfrac{2^6\cdot2^{10}}{2^{20}}=\dfrac{1}{2^4}=\dfrac{1}{16}\\ d,=\dfrac{3^{44}\cdot3^{17}}{3^{30}\cdot3^{30}}=3\\ 2,\\ a,A=\left|x-\dfrac{3}{4}\right|\ge0\\ A_{min}=0\Leftrightarrow x=\dfrac{3}{4}\\ b,B=1,5+\left|2-x\right|\ge1,5\\ A_{min}=1,5\Leftrightarrow x=2\\ c,A=\left|2x-\dfrac{1}{3}\right|+107\ge107\\ A_{min}=107\Leftrightarrow2x=\dfrac{1}{3}\Leftrightarrow x=\dfrac{1}{6}\)

\(d,M=5\left|1-4x\right|-1\ge-1\\ M_{min}=-1\Leftrightarrow4x=1\Leftrightarrow x=\dfrac{1}{4}\\ 3,\\ a,C=-\left|x-2\right|\le0\\ C_{max}=0\Leftrightarrow x=2\\ b,D=1-\left|2x-3\right|\le1\\ D_{max}=1\Leftrightarrow x=\dfrac{3}{2}\\ c,D=-\left|x+\dfrac{5}{2}\right|\le0\\ D_{max}=0\Leftrightarrow x=-\dfrac{5}{2}\)

Mấy bn help mk vs nha !!!!!!!!!!!!!!!1

Bằng -16322,21709

00000000000

a. \(=4x^2-4xy+y^2+4x^2-4xy+y^2=8x^2+2y^2\)

\(=8.\left(\frac{1}{21}\right)^2+4.\left(-0.3\right)^2=\frac{4169}{11025}\)

b, \(=\left(\frac{1}{7}xy+7yz+\frac{1}{7}xy-7yz\right)\left(\frac{1}{7}xy+7yz-\frac{1}{7}xy+7yz\right)\)

\(=\frac{2}{7}xy.14yz=4xy^2z=4.2.\left(0,25\right)^2.\left(-4\right)=-2\)

a) \(\left(0,25\right)^3.32=0,015625.32=0,5\)

b) \(\left(0,125\right)^3.80^4=0,001953125.40960000=80000\)

c) \(\frac{8^2.4^5}{2^{20}}=\frac{\left(2^3\right)^2.\left(2^2\right)^5}{2^{20}}=\frac{2^5.2^{10}}{2^{20}}=\frac{2^{15}}{2^{20}}=\frac{1}{2^5}=\frac{1}{32}\)

d) \(\frac{81^{11}.3^{17}}{27^{10}.9^{15}}=\frac{\left(3^4\right)^{11}.3^{17}}{\left(3^3\right)^{19}.\left(3^2\right)^{15}}=\frac{3^{44}.3^{17}}{3^{57}.3^{30}}=\frac{3^{61}}{3^{87}}=\frac{1}{3^{26}}\)

siêu sao đá bóng sai c và d rồi

kết quả của c=\(\frac{1}{16}\)  kết quả của d=3

\(\left(x-1\right)\left(x+1\right)-x\left(x+3\right)\)

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

\(=x^2-1-x^2-3x\)

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

\(=-3x-1\)

`!`

`(x-1)(x+1)-x(x+3)`

`= x^2+x-x-1-(x^2+3x)`

`= x^2 -1-x^2+3x`

`= 3x-1`

\(\left(5-3x\right)\left(5+3x\right)-\left(x+1\right)^3\)

\(=25-9x^2-x^3-3x^2-3x-1\)

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