What is 8.16×(10)^-6 in standard form

Find the image of a(4, -2) after it is reflected over the line y= 2, then reflected over the line x = 2. (-8,6) o (0.-2) o (0,6) (-8, -2)

Mrs. morton has a special reward system for her class. when all her students behave well, she rewards them by putting 3 marbles into a marble jar. when the jar has 100 or more marbles, the students have a party. right now, the the jar has 24 marbles. how could mrs. morton reward the class in order for the students to have a party?

[10 points, algebra 2-simplifying complex fractions]according to my answer key the restrictions are -1 and 4. but why not positive 1?