Question

Tìm x 

( 2 . x - 15 ) . 11 = 11

( x - 2010 ) . 2009 = x - 2010

( x - 5 ) . ( x - 7 ) = 0

( x - 11 ) . ( x - 2018 ) = 0

. = dấu nhân

Answer 1

(2.x - 15) . 11 = 11

2.x - 15 = 11 : 11

2.x - 15 = 1

2.x = 1 + 15

2.x = 16

x = 16 : 2 = 8

(x - 5) . (x - 7) = 0

\(\Rightarrow\orbr{\begin{cases}x-5=0\\x-7=0\end{cases}}\Rightarrow\orbr{\begin{cases}x=5\\x=7\end{cases}}\)

Answer 2

(x - 2010) . 2009 = x - 2010

2009x - 4038090 = x - 2010

2009x - x = 4038090 - 2010

2008x = 4036080

x = 4036080 : 2008

x = 2010

(x - 11) .(x - 2018) = 0

\(\Rightarrow\orbr{\begin{cases}x-11=0\\x-2018=0\end{cases}}\Rightarrow\orbr{\begin{cases}x=11\\x=2018\end{cases}}\)