Simplify 14xy^4(-14y)

$14 x y^{4} (- 14 y)$

Multiply $y^{4}$ by $y$ by adding the exponents.

Move $y$ .

$14 x (y \cdot y^{4}) \cdot - 14$

Multiply $y$ by $y^{4}$ .

Raise $y$ to the power of $1$ .

$14 x (y^{1} y^{4}) \cdot - 14$

Use the power rule $a^{m} a^{n} = a^{m + n}$ to combine exponents.

$14 x y^{1 + 4} \cdot - 14$

Add $1$ and $4$ .

$14 x y^{5} \cdot - 14$

Multiply $- 14$ by $14$ .

$- 196 x y^{5}$