Question

Tìm x ạ

Answer 1

\(b,2\left(3-x\right)^2-15=17\\ \Rightarrow b,2\left(3-x\right)^2=32\\ \Rightarrow\left(3-x\right)^2=16\\ \Rightarrow\left[{}\begin{matrix}3-x=4\\3-x=-4\end{matrix}\right.\\ \Rightarrow\left[{}\begin{matrix}x=-1\\x=7\end{matrix}\right.\\ c,5^{x-1}=4.5^{12}+5^{12}\\ \Rightarrow5^{x-1}=5.5^{12}\\ \Rightarrow5^{x-1}=5^{13}\\ \Rightarrow x-1=13\\ \Rightarrow x=14\)