1+3+9+27+......+y=1093
3x(1+3+9+27+.....+y)=1093x3
3+9+27+81+.....+3y=1093x3
=> 1093x3-1093= (3+9+27+.....3y)-(1+3+9+27+....+y)
<=> 1093x2=3y-1
<=>2186+1=3y
<=> 2187=3y
=> y=2187:3
y=729
Tìm y biết : { y + 1/3 } + { y + 1/9 } + { y + 1/27 } = 25/27
Tìm y biết: (y + 1/3) + (y + 1/9) + (y + 1/27) + (y + 1/81) = 56/81
Tìm y biết: (y + 1/3) + ( y + 1/9) + ( y + 1/27) + ( y + 1/81) = 56/81
giải hộ tớ nhé!
-^_^-
1+1/3+1/27+1/81+1/243+1/729+1/2187 = ?
A.1093/2187 B.1/729 C.1093/729 D.2186/729
Tìm y biết: \(\frac{y}{1+2}+\frac{y}{1+2+3}+....+\frac{y}{1+2+3+...+43+44}=\frac{27}{44}\)
( y +1/3) + ( y + 1/9 ) + (y+1/27) + (y+1/81)= 56/81
Tim y biet :
( y + 1/3 ) + ( y + 1/9 ) + ( y + 1/27 ) + ( y + 1/81 ) = 56/81
tìm x,y :
\(\frac{1}{2}-\left(6\frac{5}{9}+x-\frac{117}{8}\right):\left(12\frac{1}{9}\right)=0\)
\(\left(y+\frac{1}{3}\right)+\left(y+\frac{2}{9}\right)+\left(y+\frac{1}{27}\right)+\left(y+\frac{1}{81}\right)=\frac{56}{81}\)
Tìm y: biết : 9/4 - y x 5/6 = 1/2 + 1/3
