a) \(\Rightarrow2x\left(x-7\right)+5\left(x-7\right)=0\)
\(\Rightarrow\left(x-7\right)\left(2x+5\right)=0\)
\(\Rightarrow\left[{}\begin{matrix}x=7\\x=-\dfrac{5}{2}\end{matrix}\right.\)
b) \(\Rightarrow\left(x-2\right)\left(x^2+1\right)=0\)
\(\Rightarrow x=2\left(do.x^2+1\ge1>0\right)\)
c) \(\Rightarrow\left(x-3\right)\left(x-7\right)=0\)
\(\Rightarrow\left[{}\begin{matrix}x=3\\x=7\end{matrix}\right.\)
d) \(\Rightarrow\left(x-5\right)\left(x^2-1\right)=0\)
\(\Rightarrow\left(x-5\right)\left(x-1\right)\left(x+1\right)=0\)
\(\Rightarrow\left[{}\begin{matrix}x=5\\x=1\\x=-1\end{matrix}\right.\)
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