Answer
-$\frac{1}{5}$x$^{10}$y$^7$z$^2$
Work Step by Step
Divide the monomials by cancelling out common factors of the numbers and subtracting the exponents of variables.
$\frac{-8x^{12}y^{10}z^4}{40x^2y^3z^2}$=-$\frac{8}{40}$x$^{(12-2)}$y$^{(10-3)}$z$^{(4-2)}$=-$\frac{1}{5}$x$^{10}$y$^7$z$^2$
Check the answer
40x$^2$y$^3$z$^2$(-$\frac{1}{5}$x$^{10}$y$^7$z$^2$)=-$\frac{40}{5}$x$^{(2+10)}$y$^{(3+7)}$z$^{(2+2)}$=-8x$^{12}$y$^{10}$z$^4$
