If the value of y varies directly with x, which function represents the relationship between x and y when y = 16/5 and X=20

A. Y=25/4x
B. Y=116/5x
C. Y=4/25x
D. Y=64x

C. Y=4/25x

Step-by-step explanation:

If y varies directly as x, tis is expressed as;

y ∝ x

y = kx

k is the constant of proportionality

Goven

y = 16/5 and x = 20

16/5 = 20k

16 = 100k

k = 16/100

k = 4/25

Substitute k = 4/25 into the original equation

y = kx

y = 4/25 x

Hence the required expression is y = 4/25 x

b

step-by-step explanation:

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+

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