-(2x^2y)(-xy^4)

(-2r/s)(s^2/-6t)

To multiply the expressions -(2x^2y)(-xy^4), you can use the distributive property and multiply each term from the first expression by each term from the second expression. Let's break it down step by step:

1. Multiply the coefficients: -2 * -1 = 2.

2. Multiply the x-terms: x^2 * x = x^(2+1) = x^3.

3. Multiply the y-terms: y * y^4 = y^(1+4) = y^5.

So, -(2x^2y)(-xy^4) simplifies to 2x^3y^5.

Now let's move on to the expression (-2r/s)(s^2/-6t):

1. Multiply the coefficients: -2 * -1 = 2.

2. Multiply the r-terms: r * 1 = r.

3. Multiply the s-terms: s * s^2 = s^(1+2) = s^3.

4. Multiply the t-terms: 1 * -6t = -6t.

Finally, simplify the expression: (-2r/s)(s^2/-6t) becomes 2rs^3/-6t, which simplifies to -rs^3/3t.