Các câu hỏi tương tự
1X5+1X5=
1/1x5/5
B= 1/1x5+1/5x9+1/9x13+...+1/125x129
5/1x5+5/3x5+5/5x7+.....+5/99x101
1/1x5+1/5x7+1/7x9+...+1/99x101 = ?
tính nhanh:B=4/1x5+4/9x13+....+4/81x85
D= 1/1x5 + 1/5x9 + 1/9x15 + ...+ 1/21×25
Tính 3/1x5+3/5x9+3/9x13+3/13x17+3/17x21
Tìm X:
4xX/1x5+4xX/5x9+4xX/9x13+4xX/13x17=16