Question

Tìm số nguyên x biết

2x+12=3(x-7)

Answer 1

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

\(2x+12=3x-21\)

\(2x-3x=-21-12\)

          \(-x=-33\)

              \(x=33\)

Answer 2

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

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

\(\Leftrightarrow-x=-33\)

\(\Rightarrow x=33\)

Vậy \(x=33\)

Answer 3

2x²-1=49

Answer 4

2x + 12 = 3 (x - 7)

2x + 12 = 3x - 3.7

2x + 12 = 3x - 21

2x + 12 + 21 = 3x

2x + 33 = 3x

33 = 3x - 2x

x = 33