(2x+14)2=105-5=100
=> 2x+14 bằng 10 hoặc -10
Ta có :TH1 : 2x+14=10 TH2: 2x+14=-10
2x=-4 2x=-24
x=-2 x=-12
\(5+\left(2x+14\right)^2=105\)
\(\left(2x+14\right)^2=105-5\)
\(\left(2x+14\right)^2=100\)
\(\left(2x+14\right)^2=10^2\)
\(\Rightarrow2x+14=10\)
\(\Rightarrow2x=-4\)
\(\Rightarrow x=-2\)
vậy \(x=-2\)
5 + (2x + 14)^2 = 105
(2x+14)^2 = 105 - 5
(2x+14)^2 = 100
(2x+14)^2 = 10^2
=> 2x+14 = 10
2x = 10-14
2x = -4
x = (-4) : 2
x = -2
vậy.....
\(5+\left(2x+14\right)^2=105\)
\(\Rightarrow\left(2x+14\right)^2=105-5=100=\left(\mp10\right)^2\)
=>\(\orbr{\begin{cases}2x+14=10\\2x+14=-10\end{cases}}\)
=>\(\orbr{\begin{cases}2x=-4\\2x=-24\end{cases}}\)
=> \(\orbr{\begin{cases}x=-2\\x=-12\end{cases}}\)
Vậy x = -2 ; -12
\(5+\left(2x+14\right)^2=105.\)
\(\left(2x+14\right)^2=105-5.\)
\(\left(2x+14\right)^2=100.\)
\(\left(2x+14\right)=+-10.\)
\(\Rightarrow2x+14=10.\) hoặc \(2x+14=-10.\)
\(\Rightarrow2x=10-14.\) hoặc \(2x=-10-14.\)
\(\Rightarrow2x=-4.\) hoặc \(2x=-24.\)
\(\Rightarrow x=-4:2.\) hoặc \(x=-24:2.\)
\(\Rightarrow x=-2.\) hoặc \(x=-12.\)
dễ mà!
đề
suy ra:(2x+14)^2=105-5=100
sr:(2x+14)=10^2
sr2x+14=10
sr 2x=10-14=-4
sr x=-4:2=2
vậy x bằng 2
k ra 2 t/h đâu , ai ra 2 t/h là sai đó