EXERCISE: Find analytically solutions to the

$($a$)f(x)=(x-3)(x^2-x12)$

$($b$)f(x)=(x^{2}6x8)(x-4)x$

$($c$)f(x)=2x^{2}3x5$

$($d$)f(x)=x^{2}x10$

$($e$)f(x)=x^{2}3x$