Ta có : A=3/2x5+3/5x8+3/8x11+3/11x14+3/14x17+3/17x20
=> A=1/2-1/5+1/5-1/8+1/8-1/11+1/11-1/14+1/14-1/17+1/17-1/20
=> A=1/2-1/20
=> A=9/20
Vậy A=9/20
đó
Tính nhanh
A = \(\dfrac{3}{2x5}+\dfrac{3}{5x8}+\dfrac{3}{8x11}+\dfrac{3}{11x14}+\dfrac{3}{14x17}+\dfrac{3}{17x20}\)
A = 3/2x5 + 3/5x8 + 3/8x11 + 3/11x14+ 3/14x17+ 3/17x20
A nhanh tay mình cho 1 like nha
A=3/5x8 3/8x11 3/11x14 ... 3/602x605
Tinh nhanh: A=1/ 2x5 + 1/5x8 + 1/8x11 + 1/11x14 + 1/14x17
a= 3/2x5 + 3/5x8 + 3/8x11 + ... + 3/20x23 + 3/223x26 = ?
A=3/2x5+3/5x8+3/8x11+...+3/17x20
tính tổng sau cho hợp lí
A= 3/2x5+3/5x8+3/8x11+...+3/17x20
tinh nhanh a, 2/5x8+2/ 8x11 +2/ 11x14 + ... +2/ 95x98
a ] 1/2x5 +1/5x8 +1/8x11 +....+ 1/329x332
b ] S = 3/2 +3/6 +3/12 +3/20 +........+ 3/420 +3/462
c ] M = 9/8 x 16 /15 x 25/24 x ....x 400/399
giải chi tiết ra hộ mình nhé !
