45408:y+81664:y=722
=>(45408+81664):y=722
=>127072:y=722
=>y=127072:722=176
45408:y+81664:y=722
=>(45408+81664):y=722
=>127072:y=722
=>y=127072:722=176
tim a: 4/3*7+4/7*11+4/11*15+...+4/a*(a+4)=664/1995
b a+a/3+a/6+a/10+...+a/45\165/178
Tìm y biết: (y + 1/3) + (y + 1/9) + (y + 1/27) + (y + 1/81) = 56/81
( 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 y biết: (y + 1/3) + ( y + 1/9) + ( y + 1/27) + ( y + 1/81) = 56/81
giải hộ tớ nhé!
-^_^-
a) (y+1/3)+(y+2/9)+(y+1/27)+(1/81)=56/81
b) (1/2+1/4+1/8+1/16):y=1/2+1/6+1/12+1/20+...+1/132
tìm y,biết rằng:
81+81x5=\(\dfrac{y+160}{y}\)+405
yx5+y:0,25=81
yx3+y:0,2=64
1. \(\left(y+\dfrac{1}{3}\right)\)+\(\left(y+\dfrac{1}{9}\right)\)+\(\left(y+\dfrac{1}{27}\right)\)+\(\left(y+\dfrac{1}{81}\right)\)=\(\dfrac{56}{81}\)
2. 18:\(\dfrac{Xx0,4+0,32}{X}\)+5=14
3. \(\dfrac{3xX}{2}\)=\(\dfrac{2}{5}+\)X\(+\dfrac{1}{3}\)
4. X-\(\dfrac{11}{15}\)=\(\dfrac{3+X}{5}\)
tim y: (y*3 *2012):299=(81*2015) :299