2c(1+c)-(c-2)(c+4) = 2c + 2c^2 - c^2 - 2c + 8 = c^2 + 4
(y+2)²-2y (y+2) = y² + 4y + 4 - 2y² - 4y = -y²
30x+3(x-5)² = 30x + 3(x^2 - 10x + 25) = 30x + 3x^2 - 30x + 75 = 3x^2 + 75
2c(1+c)-(c-2)(c+4) = 2c + 2c^2 - c^2 - 2c + 8 = c^2 + 4
(y+2)²-2y (y+2) = y² + 4y + 4 - 2y² - 4y = -y²
30x+3(x-5)² = 30x + 3(x^2 - 10x + 25) = 30x + 3x^2 - 30x + 75 = 3x^2 + 75