Question

$frac{56 x^{3} y^{4} }{z^{5} } (- frac{ x^{2} z^{4} }{16 y^{6} })$

Answer 1

$frac{56x^3y^4}{z^5} *(- frac{x^2z^4}{16y^6} )=$
$-( frac{56x^3y^4*x^2z^4}{z^5*16y^6} )=-( frac{14x^5}{z*4y^2} )=$
$-( frac{7x^5}{z*2y^2} )=- frac{7x^5}{2y^2z}$