Question

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Tìm x:

2x + 12 = 3. (x-7)

Answer 1

\(2x+12=3\left(x-7\right)\)

\(\Leftrightarrow2x+12=3x-21\)

\(\Leftrightarrow2x-3x=-12-21\)

\(\Leftrightarrow-x=-33\)

\(\Leftrightarrow x=33\)

 bỏ dấu\(\Leftrightarrow\)cx đc nhé,lp 6 chx hok đến phương trình

 #hoktot<3# 

Answer 2

\(2x+12=3\left(x-7\right)\)

\(\Leftrightarrow2x+12=3x-21\)

\(\Leftrightarrow2x+12-3x+21=0\)

\(\Leftrightarrow-x+33=0\Leftrightarrow33-x=0\Leftrightarrow x=33\)

Answer 3

\(2x+12=3\left(x-7\right)\)

=> \(2x+12=3x-21\)

=> \(3x-2x=12+21\)

=> \(x=33\)

Answer 4

2x + 12 =3.(x - 7)

=>2x + 12 =3x - 21

=>3x-2x=21+12

=>x=33