Answer
$$-35x^6y^9$$
Work Step by Step
First off, we want to do a little rewriting so that variables are close to one another:
$$(-7)(5)(x^2)(x^4)(y^3)(y^6)$$
We now use the product rule for exponents to simplify the expression. The product rule for exponents states that if two powers are multiplied, the exponents can be added together if the bases are the same:
$$(-35)(x^{2 + 4})(y^{3 + 6})$$
Add the exponents to simplify:
$$-35x^6y^9$$
