\(\left(1-\frac{1}{4}\right).\left(1-\frac{1}{9}\right).\left(1-\frac{1}{16}\right).\left(1-\frac{1}{25}\right).\left(1-\frac{1}{36}\right)\)
\(=\frac{3}{4}.\frac{8}{9}.\frac{15}{16}.\frac{24}{25}.\frac{35}{36}=\frac{3.8.15.24.35}{4.9.16.25.36}=\frac{1.3.2.4.3.5.4.6.5.7}{2.2.3.3.4.4.5.5.6.6}\)
\(=\frac{\left(1.2.3.4.5\right).\left(3.4.5.6.7\right)}{\left(2.3.4.5.6\right).\left(2.3.4.5.6\right)}=\frac{1.7}{2.2}=\frac{7}{4}\)
\(\left(1-\frac{1}{4}\right)x\left(1-\frac{1}{9}\right)x\left(1-\frac{1}{16}\right)x\left(1-\frac{1}{25}\right)x\left(1-\frac{1}{36}\right)\)
\(=\)\(\frac{3}{4}\) x \(\frac{8}{9}\) x \(\frac{15}{16}\) x \(\frac{24}{25}\) x \(\frac{35}{36}\)
\(=\frac{7}{12}\)
P/S : Bài này mình vừa mới là cho Bạn Nguyễn Thu Trang
Tính :
( 1 - 1/4 ) x ( 1 - 1/9 ) x ( 1 - 1/16 ) x ( 1 - 1/25 ) x ( 1 - 1/36 )
= ( 4/4 - 1/4 ) x ( 9/9 - 1/9 ) x ( 16/16 - 1/16 ) x ( 25/25 - 1/25 ) x ( 36/36 - 1/36 )
= 3/4 x 8/9 x 15/16 x 24/25 x 35/36
= ( 3/4 x 8/9 ) x 15/16 x ( 24/25 x 35/36 )
= 2/3 x 15/16 x 14/15
= 2/3 x 7/8
= 7/12
tk và kb vs mk nhé! hihiii
