\(7^{2x-6}=49\)
\(=>7^{2x-6}=7^2\) hoặc \(7^{2x-6}=\left(-7\right)^2\)
\(=>2x-6=7\) hoặc \(2x-6=-7\)
\(=>2x=7+6\) hoặc \(2x=\left(-7\right)+6\)
\(=>2x=13\) hoặc \(2x=-1\)
\(=>x=\dfrac{13}{2}\) hoặc \(x=-\dfrac{1}{2}\)
Vậy \(x=\dfrac{13}{2}\) hoặc \(x=\dfrac{-1}{2}\)
\(#NqHahh\)
\(7^{2x-6}=49\)
\(\Rightarrow7^{2x-6}=7^2\)
\(\Rightarrow2x-6=2\)
\(\Rightarrow2x=2+6\)
\(\Rightarrow2x=8\)
\(\Rightarrow x=8:2=4\)
Mình xin sửa lại nha:
\(6^{2x-6}=49\)
\(=>7^{2x-6}=7^2\)
\(=>2x-6=2\)
\(=>2x=2+6\)
\(=>2x=8\)
\(=>x=8:2\)
\(=>x=4\)
72x-6=72
2x-6=2
2x= 2 + 6
2x=8
x=8 : 2
x= 4
Vậy x=4