(y²-7) ² - 4(y-7) -45

To simplify the expression (y²-7) ² - 4(y-7) -45, we will start by expanding the square: (y²-7) ² = (y²-7)(y²-7) By using the FOIL method, we get: = y^4 - 14y² + 49

Therefore, the expression becomes: (y^4 - 14y² + 49) - 4(y-7) - 45

Next, we distribute the -4 to the terms inside the parentheses: = y^4 - 14y² + 49 - 4y + 28 - 45

Simplifying further, we combine like terms: = y^4 - 14y² - 4y + 32 - 45

= y^4 - 14y² - 4y - 13

So, the simplified form of the expression is y^4 - 14y² - 4y - 13.