1, \(\left(y+7\right)\left(y-5\right)=0\)
\(\Rightarrow\left[{}\begin{matrix}y+7=0\\y-5=0\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}y=-7\\y=5\end{matrix}\right.\)
2, \(25-\left(30+x\right)=\left(-24+3\right)\)
\(\Rightarrow25-\left(30+x\right)=-21\)
\(\Rightarrow30+x=25-\left(-21\right)\)
\(\Rightarrow30+x=25+21\)
\(\Rightarrow30+x=46\)
\(\Rightarrow x=46-30\)
\(\Rightarrow x=16\)