Question

Tìm x biết

(4x+1)²-2=23

Answer 1

=>(4x+1)²=25=5²

=>4x+1=5 hoặc =-5

+)4x+1=5 =>x=1

+)4x+1=-5=>x=-3/2

vậy x=1 hoặc x=-3/2

Answer 2

(4x+1)^2 - 2= 23

=> (4x+1)^2 = 25

=> \(\orbr{\begin{cases}4x+1=5\\4x+1=-5\end{cases}}\)=> \(\orbr{\begin{cases}4x=6\\4x=-6\end{cases}}\)=> \(\orbr{\begin{cases}x=\frac{3}{2}\\x=\frac{-3}{2}\end{cases}}\)

Answer 3

(4x+1)²-2=23

(4x+1)²=23+2

(4x+1)²=25

(4x+1)²=5²

4x+1=+5

\(\Rightarrow\hept{\begin{cases}4x+1=5\\4x+1=-5\end{cases}\Rightarrow\hept{\begin{cases}x=1\\x=-1,5\end{cases}}}\)