The simplified expression is

Step-by-step explanation:
In the given expression,
, we need to distribute the
across the terms inside the parentheses. Applying the distributive property, we get
. This simplifies to
.
In the first term,
, we multiply the coefficients (-1 * 5) to get -5. Then, we add the exponents of y (3 + 3), resulting in
. So, the first term becomes
.
In the second term, (
) * (-7y), the product of the coefficients (-1 * -7) is 7, and we add the exponents of y (3 + 1) to get . Thus, the second term simplifies to
.
Lastly, in the third term, (
) * (-3), the product of the coefficients (-1 * -3) is 3. Since there is no common exponent for y, the term remains as -
.
Putting it all together, the simplified expression is
This form is the simplest representation of the original expression, combining like terms and presenting the result in descending order of exponents.