Simplify (-8xy^3)(5x^3y^2)+3x^4y^5

$(- 8 x y^{3}) (5 x^{3} y^{2}) + 3 x^{4} y^{5}$

Simplify each term.

Multiply $x$ by $x^{3}$ by adding the exponents.

Move $x^{3}$ .

$- 8 (x^{3} x) y^{3} (5 y^{2}) + 3 x^{4} y^{5}$

Multiply $x^{3}$ by $x$ .

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

$- 8 (x^{3} x^{1}) y^{3} (5 y^{2}) + 3 x^{4} y^{5}$

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

$- 8 x^{3 + 1} y^{3} (5 y^{2}) + 3 x^{4} y^{5}$

Add $3$ and $1$ .

$- 8 x^{4} y^{3} (5 y^{2}) + 3 x^{4} y^{5}$

Multiply $y^{3}$ by $y^{2}$ by adding the exponents.

Move $y^{2}$ .

$- 8 x^{4} (y^{2} y^{3}) \cdot 5 + 3 x^{4} y^{5}$

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

$- 8 x^{4} y^{2 + 3} \cdot 5 + 3 x^{4} y^{5}$

Add $2$ and $3$ .

$- 8 x^{4} y^{5} \cdot 5 + 3 x^{4} y^{5}$

Multiply $5$ by $- 8$ .

$- 40 x^{4} y^{5} + 3 x^{4} y^{5}$

Add $- 40 x^{4} y^{5}$ and $3 x^{4} y^{5}$ .

$- 37 x^{4} y^{5}$