How is the words enter and victor alike

Which of the following expressions is equal to 2x^2+8

What are the exclude value of mn+3m

[15 points]find the least common multiple of the expressions: 1. 3x^2, 6x - 18 2. 5x, 5x(x +2) 3. x^2 - 9, x + 3 4. x^2 - 3x - 10, x + 2 explain if possible