tìm x a, ( x – 2017 ) . 958 = 0 b, 959 . ( x – 7 ) = 0 c, ( x – 1 ) . ( x – 2020 ) = 0 d , 7 x + 4 x = 9900 e, 2 x + x = 6969 . là nhân

0 bình luận về “tìm x a, ( x – 2017 ) . 958 = 0 b, 959 . ( x – 7 ) = 0 c, ( x – 1 ) . ( x – 2020 ) = 0 d , 7 x + 4 x = 9900 e, 2 x + x = 6969 . là nhân”

1. $\text { a }$,  $\text { (x – 2017) . 958 = 0 }$

             $\text { ⇔  x – 2017 = 0 }$

             $\text { ⇔  x = 0 + 2017 }$

             $\text { ⇔  x = 2017}$

   $\text { Vậy x = 2017 }$

   $\text { b }$,  $\text { 959 . (x – 7) = 0 }$

             $\text { ⇔ x – 7 = 0 }$

             $\text { ⇔ x = 0 + 7 }$

             $\text { ⇔ x = 7 }$

   $\text { Vậy x = 7 }$

   $\text { c }$,  $\text { (x – 1) . (x – 2020) = 0 }$

             $\text { ⇔ \(\left[ \begin{array}{l}x – 1 = 0\\x – 2020 = 0\end{array} \right.\) }$

             $\text { ⇔ \(\left[ \begin{array}{l}x = 1\\x = 2020\end{array} \right.\) }$

   $\text { Vậy x ∈ {1 ; 2020} }$

   $\text { d }$,  $\text { 7x + 4x = 9900 }$

             $\text { ⇔ (7 + 4) . x = 9900 }$

             $\text { ⇔  11 . x = 9900 }$

             $\text { ⇔  x =  9900 : 11 }$

             $\text { ⇔  x = 900 }$

   $\text { Vậy x = 900 }$

   $\text { e }$,  $\text { 2x + x = 6969 }$

             $\text { ⇔ (2 + 1) . x = 6969 }$

             $\text { ⇔ 3 . x = 6969 }$

             $\text { ⇔ x = 6969 : 3 }$

             $\text { ⇔ x = 2323 }$

   $\text { Vậy x = 2323 }$

             

    

   Trả lời

2. $a.\ (x-2017).958=0$

   $⇒x-2017=0$
   $⇔x=2017$

   Vậy $x=2017$

   $b.\ 959.(x-7)=0$

   $⇒x-7=0$

   $⇒x=7$

   Vậy $x=7$

   $c.\ (x-1)(x-2020)=0$

   $⇔\left[ \begin{array}{l}x-1=0\\x-2020=0\end{array} \right.⇔\left[ \begin{array}{l}x=1\\x=2020\end{array} \right.$

   Vậy $x=1,x=2020$

   $d.\ 7x+4x=9900$

   $⇒11x=9900$

   $⇒x=900$

   Vậy $x=900$

   $e.\ 2x+x=6969$

   $⇒3x=6969$

   $⇒x=2323$
   Vậy $x=2323$.

   Trả lời