4. Expand and simplity by callecting like terms aा \( (x+1)(x+2) \) b) \( (y+2)\left(y^{2}-2 y-1\right) \) द7 \( (3 m-2)(m-4) \) d) \( (2 x-1)\left(x^{2}-2 x-1\right) \) (7) \( -(x-5)^{2} \)

Let's simplify each expression by expanding and collecting like terms! a) For \( (x+1)(x+2) \): Expanding gives us \( x^2 + 2x + 1x + 2 = x^2 + 3x + 2 \). b) For \( (y+2)(y^{2}-2y-1) \): Expanding gives \( y(y^2) - 2y^2 - y + 2y^2 - 4y - 2 = y^3 - 3y - 2 \). c) For \( (3m-2)(m-4) \): Expanding gives \( 3m^2 - 12m - 2m + 8 = 3m^2 - 14m + 8 \). d) For \( (2x-1)(x^2-2x-1) \): Expanding gives \( 2x^3 - 4x^2 - 2x - x^2 + 2x + 1 = 2x^3 - 5x^2 + 1 \). e) For \( -(x-5)^2 \): Expanding gives \( -(x^2 - 10x + 25) = -x^2 + 10x - 25 \). And there you go! All expanded and simplified!