Who invented the square root of negative one?

Write an equation in point-slope form for the line through the given point that has the given slope (-2,-7); m=-3/2

How do i simply this expression (quadratic formula basis) on a ti-84 or normal calculator?

Fatima plans to spend at least $15 and at most $20 dollars on sketch pads and pencils. if she buys 2 sketchpads, how many pemcils can she buy while staying in her price range? fatima can buy between and pencils. ? (type whole numbers. use ascending? order.)