Question

Mọi người ơi ! Giúp em với ạ . Em camon nha !

Answer 1

Câu b

5x-8=2x+7

<=> 3x=7+8=15

<=>x=5

Câu c:

<=>4x=3+5

<=>4x=8

<=>x=2

Câu d

<=>6=4x

<=> x=3/2

Câu e

<=> 2x+8-6x+15=3

<=>4x=20

<=>x=5

Answer 2

b)5x-8=2x+7

⇔3x=15

⇔ x=5

c)4x²+2x-5=4x²-2x+3

⇔ 4x=8

⇔ x=2

d)2x³-3x+6=2x³+x

⇔ 4x=6

⇔ \(x=\dfrac{3}{2}\)

e)2(x+4)-3(2x-5)=3

⇔ 2x+4-6x+15=3

⇔ -4x+19=3

⇔ 4x=16

⇔ x=4

Answer 3

b) Ta có: 5x-8=2x+7

\(\Leftrightarrow5x-2x=7+8\)

\(\Leftrightarrow3x=15\)

hay x=5

c) Ta có: \(4x^2+2x-5=4x^2-2x+3\)

\(\Leftrightarrow2x-5+2x-3=0\)

\(\Leftrightarrow4x=8\)

hay x=2

Answer 4

d) Ta có: \(2x^3-3x+6=2x^3+x\)

\(\Leftrightarrow-3x-x=-6\)

\(\Leftrightarrow4x=6\)

hay \(x=\dfrac{3}{2}\)

e) Ta có: \(2\left(x+4\right)-3\left(2x-5\right)=3\)

\(\Leftrightarrow2x+8-6x+15=3\)

\(\Leftrightarrow-4x=3-15-8=-20\)

hay x=5