Is this an example of direct variation? f(x)=2xy

Simplify the expression. -2/5(10+15m-20n)

Atriangle has verticals at b(-3,0), c(2,-1), d(-1,2). which transformation would produce an image with verticals b”(-2,1), c”(3,2), d”(0,-1)?

Grace is standing 18 feet from a lighthouse and kelly is standing 10 feet from grace. the angle that grace looks up to see the top of the lighthouse is 45°. the angle that kelly looks up to see the top of the lighthouse is y°. find the height, h, of the lighthouse. find the angle, rounded to the nearest tenth of a degree, in which kelly looks up to the top of the lighthouse. to the nearest tenth of a degree, find the value of x° . in two or more sentences, explain your calculations