Question

[Nguyễn Lương Thu Huyền]

Tính nhanh:

         25 * 4- 0,5 *40 *5 *0,2*20*0,25

Trên  

1+2+4+8+.....+128+256

Bài toán về phân số nhé 

Giúp mks giải nha ai nhanh mks tick cho

Answer 1

[Thanh Tùng DZ]

\(\frac{25\times4-0,5\times40\times5\times0,2\times20\times0,25}{1+2+4+8+...+128+256}\)

\(=\frac{100-\left(20\times5\right)\times\left(0,5\times0,2\times0,25\times40\right)}{1+2+4+8+...+128+256}\)

\(=\frac{100-100\times\left(\frac{1}{40}\times40\right)}{1+2+4+8+...+128+256}\)

\(=\frac{100\times\left(1-1\right)}{1+2+4+8+...+128+256}\)

\(=0\)

Answer 2

[nguyen thi bao tien]

\(\frac{25\times4-0,5\times40\times5\times0,2\times20\times0,25}{1+2+4+8+...128+256}\)

\(=\frac{100-\left(0,5\times20\right)\times\left(40\times0,25\right)\times\left(5\times0,2\right)}{1+2+4+8+...+128+256}\)

\(=\frac{100-10\times10\times1}{1+2+4+8+...+128+256}\)

\(=\frac{100-100}{1+2+4+8+...+128+256}\)

\(=\frac{0}{1+2+4+8+...+128+256}=0\)