`60% - 2 1/2 - 1/4 - 0,25:5/12`

`=3/5-5/2-1/4-1/4 . 12/5`

`=3/5-5/2-1/4-3/5`

`=(3/5-3/5)-(5/2+1/4)`

`=0-(10/4+1/4)`

`=-11/4`

a,\(\frac{1}{6}-\frac{1}{4}+\frac{1}{12}\)

\(=\frac{2}{12}-\frac{3}{12}+\frac{1}{12}\)

\(=0\)

\(b,\frac{1}{2}-0.25+12\)

\(=\frac{1}{2}-\frac{1}{4}+\frac{12}{1}\)

\(=\frac{2}{4}-\frac{1}{4}+\frac{48}{4}\)

\(=49\)

c, \(-\frac{3}{8}+\left(\frac{1}{2}-\frac{3}{4}\right)\)

\(=-\frac{3}{8}+\left(\frac{4}{8}-\frac{6}{8}\right)\)

\(=-\frac{5}{8}\)

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

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

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

a)2/9-(-4/9)=6/9=2/3

b)(-1/24+0,25+1 1/12):(-1/2)2

=(-1/24+6/24+26/24):(-1/2).2

=31/24.-2.2

=-31/12.2

=-31/6

c)3/13.(-5/9)+10/13.(-5/9)+(-4/9)

=-5/9(3/13+10/13)+(-4/9)

=-5/9.1+(-4/9)

=-1

1.

a)2/9-(-4/9)=6/9 

b)(-1/24+0,25+11/12):(-1/2)2

=1,125:-1

=-1,125

c) 3/13.-5/9+10/13.-5/9+-4/9

=-5/9.(3/13+10/13)+4/9

=5/9.1+4/9

=5/9+4/9

=9/9=1

2.

a)-41/5:x=51/4

           x=51/41.-41/5

           x=-1

    vậy x=-1                                    

b)7/12-5/12.x=1/12

          5/12.x=1/12+7/12

          5/12.x=6/12

                 x=6/12:5/12

                 x=6/12.12/5

                 x=6/5

  vậy x=6/5

Sắp xếp: \(-\dfrac{9}{8};-0,5;-0,25;-\dfrac{5}{24};0;\dfrac{1}{48};\dfrac{1}{2};\dfrac{2}{3};\dfrac{5}{6};\dfrac{13}{12}\)