This equation shows how the cost of a photography session is related to its duration in hours. c = 20d

The variable d represents the duration of the session in hours, and the variable c represents the cost. What is the duration, in hours, of a photography session that costs $20?

1 hour

Step-by-step explanation:

c= 20d

here, c=$20

$20=20d

or, d= 1 hr

geometry: triangles

solvers

lessons

answers archive

call the larger triangle abc

then the smaller triangle cde is similar to abc (all angles are equal, aaa).  

ab is the side that is 36, and we wish to find de, the side corresponding to ab

area_cde = area_abc - area_cde --> area_abc / area_cde = 2

let x=length of de

ratio of areas = (ratio of sides)^2

+2+=+%2836%2fx%29%5e2+

+2+=+1296%2fx%5e2+

++x%5e2+=+1296%2f2+=+648+

25.45584