Bài 1 20/11/2021 Bởi Ariana Bài 1 a,6.(x-2)-2=20-4x b,x.(x+5)<0 Bài 2:Tìm x∈Z để a,1:(x-1) có giá trị nguyên b,-3:(x-2) có giá trị nguyên
Bài 1 : a) $6.(x-2)-2=20-4x$ $\to 6x-14=20-4x$ $\to 10x =34$ $\to x= 3,4$ b) $x.(x+5) < 0 $ $⇔ -5 <x<0$ Bài 2 : a) $1 \vdots x-1$ $\to x-1 \in \{-1,1\}$ $\to x \in \{0,2\}$ b) $-3 \vdots x-2$ $\to x-2 \in \{-1,1,-3,3\}$ $\to x \in \{1,3,-1,5\}$ Bình luận
bài 1:a) 6(x-2) -2 = 20-4x <=> 6x -12 -2 = 20 -4x <=> 6x + 4x = 12 + 2 + 20 <=> 10x = 34 <=> x = 3,4 b) x (x+5) <0 <=> \(\left[ \begin{array}{l}x<0\\x<-5\end{array} \right.\) Bình luận
Bài 1 :
a) $6.(x-2)-2=20-4x$
$\to 6x-14=20-4x$
$\to 10x =34$
$\to x= 3,4$
b) $x.(x+5) < 0 $
$⇔ -5 <x<0$
Bài 2 :
a) $1 \vdots x-1$
$\to x-1 \in \{-1,1\}$
$\to x \in \{0,2\}$
b) $-3 \vdots x-2$
$\to x-2 \in \{-1,1,-3,3\}$
$\to x \in \{1,3,-1,5\}$
bài 1:
a) 6(x-2) -2 = 20-4x
<=> 6x -12 -2 = 20 -4x
<=> 6x + 4x = 12 + 2 + 20
<=> 10x = 34
<=> x = 3,4
b) x (x+5) <0
<=> \(\left[ \begin{array}{l}x<0\\x<-5\end{array} \right.\)