Please help me in questions 19, 21, 24 and i’ll mark u as brainliest i promise

If x=-3 is the only x-intercept of the graph of a quadratic equation, which statement best discribes the discriminant of the equation?

How do businesses a country's economy? a. by investing in goods and services b. by increasing the unemployment rate c. by making profits

Find the magnitude, correct to two decimal places, made by each of the following with positive direction of the x axis a) y= x the answer is 45° but i don’t know how