To factor $ 24xy-28x+30y-35 $ we can use factoring by grouping.
Group $ \color{blue}{ 24xy }$ with $ \color{blue}{ -28x }$ and $ \color{red}{ 30y }$ with $ \color{red}{ -35 }$ then factor each group.
$$ \begin{aligned} 24xy-28x+30y-35 &= ( \color{blue}{ 24xy-28x } ) + ( \color{red}{ 30y-35 }) = \\ &= \color{blue}{ 4x( 6y-7 )} + \color{red}{ 5( 6y-7 ) } = \\ &= (4x+5)(6y-7) \end{aligned} $$