Answer:
So, the simplified expression is: 5x(5x - 4y) - 7y(3y + z)
Explanation:
To simplify the expression 25x^2 - 20xy - 21y^2 + 10yz - z^2, we can combine like terms.
First, let's group the terms with similar variables: 25x^2 - 20xy - 21y^2 + 10yz - z^2 The terms with x^2, xy, and y^2 can be combined: (25x^2 - 20xy - 21y^2) + (10yz - z^2) Now, let's factor out any common factors within each group: 5x(5x - 4y) - 7y(3y + z)
So, the simplified expression is: 5x(5x - 4y) - 7y(3y + z)