Question

[Đỗ Nguyễn Quỳnh Anh]

Bài 12 : Tính nhanh 

a) (1-3/4) x (1-3/7) x (1-3/10) x (1-1/13) x ........ x (1- 3/97) x ( 1-3/100)

Answer 1

[T.Ps]

#)Giải :

\(\left(1-\frac{3}{4}\right)x\left(1-\frac{3}{7}\right)x\left(1-\frac{3}{10}\right)x\left(1-\frac{1}{13}\right)x...x\left(1-\frac{3}{100}\right)\)

\(=\frac{1}{4}x\frac{4}{7}x\frac{7}{10}x...x\frac{94}{97}x\frac{97}{100}\)

\(=\frac{1x4x7x...x94x100}{4x7x10x...x97x100}\)

\(=\frac{1}{100}\)

           #~Will~be~Pens~#

Answer 2

[Kiệt Nguyễn]

\(\left(1-\frac{3}{4}\right)\left(1-\frac{3}{7}\right)\left(1-\frac{3}{10}\right)\left(1-\frac{1}{13}\right)...\left(1-\frac{1}{97}\right)\left(1-\frac{3}{100}\right)\)

\(=\frac{1}{4}.\frac{4}{7}.\frac{7}{10}.\frac{10}{13}...\frac{94}{97}.\frac{97}{100}\)

\(=\frac{1}{100}\)