Question

tìm x

x + 3^2 = 7 - x

[3x +1,5] :3 1/5= 5/8

2 /x-1/  -7 = -3

Answer 1

\(x+3^2=7-x\)

\(x+x=7-9\)

\(2x=-2\)

\(x=-1\)

Answer 2

\(2\left|x-1\right|-7=-3\)

\(2\left|x-1\right|=4\)

\(\left|x-1\right|=2\)

\(\orbr{\begin{cases}x-1=2\\x-1=-2\end{cases}}\)

\(\orbr{\begin{cases}x=3\\x=-1\end{cases}}\)

Answer 3

1) x + 3^2 = 7 - x

<=> x + 9 = 7 + (-x)

<=> x + 9 = -x + 7

<=> x + 9 + x = 7

<=> 2x + 9 = 7

<=> 2x = 7 - 9

<=> 2x = -2

<=> x = (-2) : 2

<=> x = -1

3) 2|x - 1| - 7 = -3

<=> 2|x - 1| = -3 + 7

<=> 2|x - 1| = 4

<=> |x - 1| = 4 : 2

<=> |x - 1| = 2

<=> x - 1 = -+2

<=> x - 1 = 2 hoặc x - 1 = -2

       x = 1 + 2         x = -2 + 1

      x = 3                x = -1

=> x = 3 hoặc x = -1