Tính :
N = ( 1/2x4 + 1/4x6 + 1/6x8 + 1/8x10 + ....... + 1/98 X 100 ) : ( 1/2 + 1/4 + 1/8 + 1/16 + ........ + 1/512 )
So sánh:
A=\(\dfrac{1}{1x2}\)+\(\dfrac{1}{2x3}\)+.....+\(\dfrac{1}{49x50}\) với 1
B=\(\dfrac{1}{2x4}\)+\(\dfrac{1}{4x6}\)+.....+\(\dfrac{1}{46x48}\) với \(\dfrac{1}{4}\)
C=\(\dfrac{1}{6}\)+\(\dfrac{1}{12}\)+.....+\(\dfrac{1}{110}\)+\(\dfrac{1}{122}\) với \(\dfrac{1}{2}\)
Giải tất cả các câu đầy đủ phép tính giúp mik nha. C.ơn
4/2x4+4/4x6+4/6x8+...+4/18 x20 = ?
tính : a, 4/2x4+4/4x6+4/6x8+......+4/16x18+4/18x20
b, 1/2+1/6+1/12+1/20+......+1/90
Bài 1 tìm y
a) (1/2x4+1/4x6+1/6x8+1/8x10)x y =1/3
b) y:8+y x8-56,78=69,11x2
Tính nhanh:
\(\frac{1x2+2x4+3x6+4x8}{2x3+4x6+6x9+8x12}\)
TÍNH NHANH:1+1x2+2+2x3+6x8+5x5+9x2-3-8-1-1-3-4+6-8+5-7+6+56x10+23x10+135x100+234x100+1005x1000+10000x10000=?
tìm y :( 1/2x4 + 1/4x6 + 1/6x8 + 1/8x10 ) x y = 1/3
sos cố gắng giúp mik vs . mình cảm ơn
2/2x4+2/4x6+2/6x8..................2/2014x2016