Everyone Andy’s classroom has to do a project. Out of the 20 students 80% have completed their assignment. How many students still need to complete their project?

56

step-by-step explanation:

the first one, all those points on the line just make a strait line.

multiply then divide

step-by-step explanation:

step-by-step explanation:

let pq = qr = rs = x, and xz = y and zu = z.

if the horizontal lines are parallel, then corresponding segments are in proportion:

substitute:

therefore 3 = y = z.

xu = y + z → xu = 3 + 3 = 6