can I get steps and answer 4,6,7 thank you very much.

4. Find the discriminant of 3x2 + 6 = 0. Use it to determine the nature of the roots for each quadratic equation. Do not solve the equation.

6. Adine made one or more errors in her work while completing the square. Find the first line with her error, identify any further errors and correct them: Line 1 y = x2 + 6x +14 Line 2 y = (x2 + 3x + 3 - 3) + 14 Line 3 y = (x + 3)2 + 14 - 3 Line 4 y = (x + 3)2 + 11

7. A local store sells key chains for $12. At this price, the store sells and average of 120 key chains each month. Market research says that for every $1 increase in price, the manager of the store can expect to sell five fewer key chains each month. Write a quadratic function to model the revenue in terms of the increase in price.