\(\frac{3.5.7+6.10.14+9.15.21}{5.7.9+10.14.18+15.21.27}\)
= \(\frac{3.5.7+3.2.5.2.7.2+3.3.5.3.7.21}{5.7.9+5.2.7.2.9.2+5.3.7.3.9.3}\)
= \(\frac{3.5.7+3.5.7.2.2.2+3.5.7.3.3.3}{5.7.9+5.7.9.2.2.2+5.7.9.3.3.3}\)
= \(\frac{3.5.7+3.5.7.8+3.5.7.27}{5.7.9+5.7.9.8+5.7.9.27}\)
= \(\frac{3.5.7.\left(1+8+27\right)}{5.7.9.\left(1+8+27\right)}\)
= \(\frac{3.5.7.36}{5.7.9.36}\)
= \(\frac{1}{3}\)
A=\(\frac{165cx1015-168x5+1005}{83x1026x2-166x5-59-107}\)
B=\(\frac{4x\left[2x29x39+2x59x79\right]}{9x29x39+9x9x79-29x39-59x79}\)
C=\(\frac{1x3x5+2x6x10+3x9x15}{3x5x7+6x10x14+9x15x21}\)
Chứng minh rằng:A=36/1x3x5+36/3x5x7+36/5x7x9+....+36/25x27x29
tính nhanh :
4/1x3x5 + 4/3x5x7 + 4/5x7x9 + 4/7x9x11 + 4/9x11x13 .
4/1x3x5 + 4/3x5x7 + 4/5x7x9 + 4/7x9x11 + 4/9x11x13
\(\dfrac{4}{1x3x5}+\dfrac{4}{3x5x7}+\dfrac{4}{5x7x9}+\dfrac{4}{9x11x13}\)
tính nhanh 4/1x3x5+4/3x5x7+4/5x7x9+4/7x9x11+4/9x11x13
\(\frac{4}{1x3x5}\)+\(\frac{4}{3x5x7}\)+\(\frac{4}{5x7x9}\)+......+\(\frac{4}{93x95x97}\)+\(\frac{4}{95x97x99}\)
4/1x3x5 + 4/3x5x7 + 4/5x7x9 + 4/7x9x11 + 4/9x11x13 . Tính nhanh nhé
Cho
A=4/3x5x1+4/3x5x7+4/5x7x9+4/7x9x11+4/9x11x13
Ai tính đc tik cho
