Bài kia làm nhầm rồi,sửa lại từ dòng 4:
\(4+x=25\)
\(x=21\)
Câu 2:
\(\left(-13x^4y^m\right)\left(-3x^ny^6\right)=39x^{15}y^8\)
\(\left[\left(-13\right)\left(-3\right)\right]\left[x^4x^n\right]\left[y^my^6\right]=39x^{15}y^8\)
\(39x^{4+n}y^{m+6}=39x^{15}y^8\)
\(\Rightarrow\left\{{}\begin{matrix}4+n=15\\m+6=8\end{matrix}\right.\Rightarrow\left\{{}\begin{matrix}n=11\\m=2\end{matrix}\right.\)
Vậy \(\left(m,n\right)=\left(2;11\right)\)
#hoctotnhe
Câu 1:
\(3n^4.y^6.n^x.y^8=3n^{25}.y^{14}\)
\(3n^{4+x}.y^{14}=3n^{25}.y^{14}\)
\(n^{4+x}=n^{25}\)
\(4+n=25\)
\(n=21\)
