Question

Tìm x:

|x + 2.5| = 35

Answer 1

\(\left|x+2.5\right|=35\)

\(\left|x+10\right|=35\)

\(\Rightarrow\left[\begin{matrix}x+10=35\Rightarrow x=35-10\\x+10=-35\Rightarrow x=-35-10\end{matrix}\right.\)

\(\Rightarrow\left[\begin{matrix}x=25\\x=-45\end{matrix}\right.\)

Answer 2

|x + 2.5| = 35

|x + 10| = 35

Vì |-35| = |35| = 35

\(\Rightarrow\) x+10 \(\in\){-35;35}

* Nếu x+10 = -35

x = -35 - 10

x = -45

*Nếu x+10 = 35

x = 35 - 10

x = 25

Vậy x \(\in\){-45;25}

Answer 3

\(\left|x+2.5\right|=35\)

\(\left|x+10\right|=35\)

\(\Rightarrow\left[\begin{matrix}x+10=35\\x+10=-35\end{matrix}\right.\)

\(\Rightarrow\left[\begin{matrix}x=35-10\\x=-35-10\end{matrix}\right.\)

\(\Rightarrow\left[\begin{matrix}x=25\\x=-45\end{matrix}\right.\)