Question

Tìm x, biết :

a,|x+1|= 2x

b,|x-2|=3x

c,|x+3|=-4x

d,|2x-4|=x

Answer 1

Tìm x, biết :

a,|x+1|= 2x

Vì \(|x+1|\) \(\ge\) 0 \(\Rightarrow\) x \(\ge\) 0

\(\Rightarrow\) x+1=2x \(\Rightarrow\) x =1

b,|x-2|=3x

Vì \(|x-2|\ge0\Rightarrow x\ge0\)

\(\Rightarrow\) x-2 = 3x \(\Rightarrow\) -2x = -2 \(\Rightarrow\) x=1

Answer 2

Tìm x, biết :

a,|x+1|= 2x

Vì |x+1||x+1| ≥ 0 x ≥0

⇒x+1=2x ⇒x =1

b,|x-2|=3x

Vì |x−2|≥0⇒x≥0

⇒ x-2 = 3x ⇒⇒ -2x = -2 ⇒ x=1