The vertices of a triangle are a(5, –4), b(7, 0), and c(1, –2). if the triangle is a right triangle, which vertex is the right angle?

The variable z is directly proportional to x, and inversely proportional to y. when x is 4 and y is 13, z has the value 1.2307692307692. what is the value of z when x= 9, and y= 20

Imagine a new pasture with grass growing on it. every day after the seeds have germinated, the number of blades of grass in the pasture triples. after 18 days, the entire pasture is completely covered in grass. how many days did it take for the pasture to be one-third covered in grass?

Julius sold five times as many computers as sam sold last year. in total, they sold 78 computers. how many computers did julius sell?