Question

(1/15+1/35+1/63) ×X = 1

X là gì vậy?

Answer 1

( 1/15 + 1/35 + 1/63 ) x X = 1 ( 1 / 3x5 + 1/5x7 + 1/7x9 ) x X = 1 ( 1/3 - 1/5 + 1/5 - 1/7 + 1/7 - 1/9 ) x X = 1 ( 1/3 - 1/9 ) x X = 1 2/9 x X = 1 X = 1 : 2/9 X = 9/2 X là 1 số cần tìm

Answer 2

1/2 ( 1/3 -1/5 + 1/5-1/7+1/7 -1/9) xX=1 

1/2( 1/3 -1/9) xX=1

1/9 x X=1 

X= 1:1/9 =9

Answer 3

\(\left(\frac{1}{15}+\frac{1}{35}+\frac{1}{63}\right)\cdot x=1\)

\(=\frac{1}{9}\cdot x=1\)

\(\Rightarrow x=9\)